Chapter I: Front Matter (1)

TRANSCRIBER’S NOTE

Italic text is denoted by _underscores_.

Footnote anchors are denoted by [number], and the footnotes have
been placed at the end of the book.

Chapter headings have been made consistent, with the title on a
single line and the author on the following line.

Some minor changes to the text are noted at the end of the book.

Volume I of this set of four volumes can be found in Project
Gutenberg at: https://www.gutenberg.org/ebooks/74571

Volume II can be found in Project Gutenberg at:
https://www.gutenberg.org/ebooks/77792

1, Boletus Satanus; 2, Agaricus Muscarius; 3, Lycoperdon; 4, Morchella Esculenta; 5, Belvella; 6, Agaricus Campestris; 7, Phallus; 8, Agaricus Phalloides; 9, Boletus Edulis; 10, Rhizopogon (_Truffle_)]

THE STORY OF
THE UNIVERSE

_Told by Great Scientists
and Popular Authors_

COLLECTED AND EDITED

_By_ ESTHER SINGLETON

Author of “Turrets, Towers and Temples,” “Wonders of Nature,”
“The World’s Great Events,” “Famous Paintings,” Translator
of Lavignac’s “Music Dramas of Richard Wagner”

_FULLY ILLUSTRATED_

VOLUME III

THE
EARTH’S
GARMENT:
FLORA

P. F. COLLIER AND SON
NEW YORK

COPYRIGHT 1905
BY P. F. COLLIER & SON

ILLUSTRATIONS

Mushrooms and Fungi _Frontispiece_

Familiar Trees _Opposite p._ 901

Herbs, Useful and Medicinal ” 949

Flowers, Curious and Beautiful ” 997

Cacti, Rare Flowers, and Fuci ” 1045

Cereals and Food Plants ” 1093

Bacteria and Vegetable Germs ” 1141

Nuts and Fruits ” 1213

Lichens ” 1261

CONTENTS

THE VEGETABLE KINGDOM. David Robertson 859

FLORA OF THE EARLY MESOZOIC. Sir J. William Dawson 871

EXISTING LIFE-FORMS OF PLANTS. Edward Clodd 887

PLANT GEOGRAPHY. Louis Figuier 898

ZONES OF VEGETATION. M. J. Schleiden 930

PHYSIOGNOMY OF PLANTS. Alexander von Humboldt 946

THE GENESIS OF FLOWERS. Alexander S. Wilson 957

LIFE HISTORY OF PLANTS. E. W. Prevost 968

LIFE-FORMS OF PLANTS. Edward Clodd 975

CLASSIFICATION OF PLANTS. Louis Figuier 984

FRUITS AND SEEDS. Lord Avebury 1002

LEAVES. R. Lloyd Praeger 1016

WIND-FERTILIZED FLOWERS. Alexander S. Wilson 1027

MOVEMENTS OF PLANTS. David Robertson 1037

MOVEMENT IN PLANTS. Charles Darwin 1045

FLOWER COLORATION. Alexander S. Wilson 1061

QUEER FLOWERS. Grant Allen 1068

ATHENA IN THE EARTH. John Ruskin 1077

PROGRESS OF CULTIVATION. Alphonse de Candolle 1091

VEGETABLE MIMICRY AND HOMOMORPHISM. Alexander S. Wilson 1099

THE BAMBOO AND PLANT GROWTH. R. Camper Day 1114

THE REIGN OF EVERGREENS. Grant Allen 1125

OUR MICROSCOPIC FOES. A. Winkelried Williams 1131

FOREST FORMATIONS. M. J. Schleiden 1135

THE HIGH WOODS. Charles Kingsley 1146

MILK-SAP PLANTS. M. J. Schleiden 1161

NUTS. Grant Allen 1174

THE CACTUS TRIBE. M. J. Schleiden 1180

FUNGI. Hugh Macmillan 1189

FAIRY RINGS. A. B. Steele 1204

LICHENS. Hugh Macmillan 1208

MOSSES. Hugh Macmillan 1220

EUROPEAN SEA-WEEDS. P. Martin Duncan 1230

SARGASSUM. Cuthbert Collingwood 1263

GLOSSARY OF BOTANICAL TERMS 1269

THE STORY OF THE UNIVERSE

(VOLUME THREE)

THE STORY OF THE UNIVERSE

THE VEGETABLE KINGDOM
--DAVID ROBERTSON

There is perhaps scarcely any science that can be more within the reach of the means of the humblest student than the science of botany. A pocket lens, a sharp penknife, and a book descriptive of the flora of the district or country where one lives will form a sufficient equipment to enable the student to name and classify whatever plants he may meet with in his rambles in search of them.

It is by no means intended to imply that finding out the names of plants and being able to classify them constitute the whole science of botany. The truth is that many of the problems in connection with classification are most abstruse, so much so that even now the most recent and generally received system of classification can only be considered provisional. This is especially the case in regard to the lower forms of vegetable life. The life-history of many of the most minute and lowly plants is but imperfectly known, owing to their extreme minuteness and the different forms which they assume at the various stages of their life-history.

This, however, does not detract from the pleasure which any one may derive from being able to describe and name any flowering plants which are to be found in any country at certain seasons.

The dependence of mankind on plants is too obvious to require mention.

To a large extent the vegetation of a district determines its character; for without plants no landscape would possess any particular attractiveness, and every one knows the depressing effect produced by a barren, treeless waste. The contrast between this and fields rich in pasture has occurred to every one; and a well-wooded country never fails to please the eye of the observer.

Mighty forests, teeming with life, have a powerful influence on the imagination; and the value of forests both as regards their effect on climate and their economic importance has been so thoroughly recognized that in the case of India stringent measures have been adopted for their preservation.

Some knowledge of plant life also enables one to guard against the evil and often fatal effects produced by eating poisonous fruits and poisonous fungi.

Some of the lowly organized flowerless plants are man’s most deadly and insidious enemies. These from their excessive minuteness are quite invisible to the naked eye.

Before proceeding further, it will be necessary to give a brief account of the different parts which go to compose the complete flowering plant. The reader who desires a full and detailed account of the different organs of the flowering and flowerless plants will find this in any standard text-book of botany.

We will take any full-grown flowering plant and begin with the root.

The root may be called the descending portion of the axis.

The ascending portion of the axis is usually supplied with leaves, flowers, and green coloring matter, whereas the root is usually devoid of these.

The root generally penetrates into the soil and fulfils a double function.

It is by means of the roots that the plant is attached to the earth and prevented from being blown about by the winds.

In the case of large forest trees, the far-spreading roots have an immense power of resistance. The large surface of a giant tree in full leaf has to endure an enormous lateral pressure during a high wind, and even hurricanes may fail to uproot a large tree, which they may snap asunder. Not only does the root by penetrating the soil attach the plant to the earth, but it absorbs nourishment from the soil for the support of the plant. The root, therefore, fulfils a double function.

The root is at first furnished with a conical hood of cellular tissue, _i. e._, tissue consisting entirely of cells or little closed bags made up of an outside wall and contents.

The root cup is well seen in some kinds of water-plants, such as duckweed.

There are plants whose roots do not descend. Certain plants hang from the branches of trees, and though they have roots these roots never penetrate the soil. Plants of this kind are called Epiphytes (Greek _epi_, upon, and _phyton_, plant). Aerial orchids, which grow in warm and moist parts of India and other countries, are attached to branches of trees or other kinds of support, and their roots hang down from the peculiar stems and are very soft and delicate at the tips.

It must be borne in mind that there is no absolute distinction between root and stem; for some trees have roots which form lateral buds, viz., _Pyrus japonica_, _Maclura aurantiaca_, and many others.

This is quite in accordance with the fact that in the organic world different organs frequently shade into one another.

The true root of the plant in its earliest state of existence, that is, as it exists in the seed prior to germination, is the downward prolongation of the axis.

In the case of the division of flowering plants called Monocotyledons (Greek _monos_, single, and _kotyledon_, seed-leaf), and in such so-called flowerless plants as ferns, the lower end of the axis soon ceases to grow and the roots which supply these plants with nourishment are really lateral growths. The roots of plants are variously named. Sometimes the branches of the roots are small, and the central axis thick and of considerable length. This kind of root is named a tap-root, and may be well seen in the carrot.

In the turnip, beet, and other plants, where this organ is developed in such a manner as to serve as a reservoir of nutriment, the root is tuberous.

Many roots are fibrous; this may be well seen in grasses.

The perennial woody forms of fibrous roots are very characteristic of shrubby Dicotyledons (plants with two seed-leaves).

Leaves are of two kinds, namely, foliage-leaves and flower-leaves.

A leaf is generally a broad, flat, horizontal surface. It is usually thin, and can be divided by a perpendicular plane, the median plane, into two similar halves.

When the leaves are what is called symmetrical, the parts into which they are divided are counterparts.

If one of these parts were held in front of a looking-glass, the reflected image of this part would represent the part from which it had been separated.

Many leaves, however, can not thus be divided. When this is the case they are said to be unsymmetrical.

The tropical plant begonia affords an excellent example of an unsymmetrical leaf.

The leaves of the spruce are not flat but needle-shaped.

In rushes and many species of stone-crops the leaves are cylindrical or round.

The leaf consists of three parts, viz., the sheath, the stalk or petiole, and the lamina or blade. The sheath incloses the stem at the insertion of the leaf, and has a tubular or sheath-like form. It is well seen in grasses and such plants as celery, corn, parsnip, carrot, and other plants belonging to the _Umbelliferæ_ [Lat. _umbella_ (_umbra_, shade), little shade, and _ferre_, to bear].

The leaf-stalk is narrow, and has a semi-cylindrical or prismatic form, bearing at its end the expanded leaf.

When the stalk is flattened and resembles a leaf, as in the case of the Australian acacias, it is termed a phyllode (Greek _phyllon_, a leaf, and _eidos_, form).

Many leaves have no sheath, but only the stalk and the blade. This is the case in the maple and gourd.

The leaves of the grasses have no stalk, but only sheath and blade.

The blade is often the only part present, as in the tobacco plant and tiger-lily. Small appendages, looked upon as belonging to the sheath, are frequently present, and are termed stipules (from Lat. _stipula_, blade). Leaves having these appendages are called stipulate, and leaves devoid of them are exstipulate (from Lat. _ex_, privative, without, and _stipula_, blade).

A few plants, such as grasses, have a small outgrowth from the inner upper surface of the leaf at the part where the sheath and the blade are joined. This outgrowth is named a ligule (from Lat. _ligula_, a little tongue).

If a leaf is carefully examined it will be found that the internal tissues differ in character. The fundamental tissue is generally green, and is named the messophyll (Greek, _mesos_, or _messos_, middle, and _phyllon_, leaf).

It will be seen that bands run through the fundamental tissue called the veins of the leaf. These veins consist of what are termed fibro-vascular bundles. They endure longer than the fundamental tissue, and may frequently be seen after the leaf is withered and dead, forming the skeleton of the leaf.

The arrangement of the veins or fibro-vascular bundles is characteristic of large groups of plants.

In the narrow linear leaves of grasses the stronger veins run almost parallel. In broad leaves, such as those of the lily-of-the-valley, the veins curve, but do not form a network of tracery as in oaks and other Dicotyledons. The margin of leaves is frequently divided, but the technical terms used in describing such leaves can be found in any text-book of botany. They may either be simple or compound. A simple leaf consists of a single lamina, however much it may be divided, provided the divisions do not extend to the central vein or midrib. A leaf is compound when, besides the principal leaf-stalks, a number of lateral leaf-stalks exist bearing at their ends laminæ. The leaves of many plants are compound. The sensitive plant (_Mimosa pudica_) furnishes an excellent example of the compound leaf.

The characteristic color of foliage leaves is green, and they are so arranged as to receive as much sunlight as possible. The importance of the plant receiving a good supply of light will be referred to when treating of the growth of plants. It is as true of plants as of animals that the organs most suitable for their surroundings are so arranged as to be most advantageous to the individual. Had leaves been placed vertically they would only have received diffused sunlight instead of the direct rays of the sun. No vegetable life could exist but for the sun, as plants not only require light but heat as well.

When the foliage leaves are small they are very numerous, as may be seen in conifers; and when these leaves are large they are not nearly so numerous as, for example, in the sunflower.

Sometimes leaves may consist of scales. These scales are always found on stems growing underground, as in the onion; but they sometimes occur on stems growing above-ground.

Such plants as _Orobanche_ and _Neottia_ have no other kind of leaves except scales.

The leaves are developed very near the apex of the growing stem.

The portions of the stem which lie between the leaves are termed the internodes, and the parts where the leaves are inserted are termed the nodes.

Leaves are arranged in various ways, intimately connected with the order of their development. They may be developed so that three or more are at the same level on the stem; this arrangement is termed a _whorl_. Or they may be developed singly; this arrangement is termed _scattered_. For a full account of the various leaf-arrangements any text-book on botany may be consulted.

We have here merely referred to some of the more obvious arrangements of the leaves.

Certain leaves possess a remarkably abnormal shape; for example, stone-crops have cylindrical leaves; if the leaf of an agave is cut across, the section is triangular; leeks, again, are tube-shaped; the central cavity being due to the rapid growth of the outer tissue. These leaves are all juicy or succulent; certain other leaves are leathery, that is, they have a harder and thicker epidermis than the succulent leaves, and may last for several years, as, for example, in the holly and box.

Spines and tendrils are modifications of leaves, or parts of leaves. The tendrils are formed out of entire leaves, midribs, leaflets, or stipules. Both spines and tendrils, however, may be modified branches of the stem.

In buds the leaves are packed or folded in various ways. This is best seen before the buds are opened in spring. The buds may then be pulled carefully to pieces, and in this way the manner in which the leaves are folded can be studied.

We now come to the flower.

Flowers consist of leaves modified in different ways.

Take, for example, the flower of the orange. The flower will be seen to be borne on a short branch which serves as the stalk, and is distinguished by the name of peduncle (from Lat. _pedunculus_, little stalk). It will be seen that there are no internodes between the flower-leaves.

The lowest and outermost part of the flower forms a little cup having upon its margin fine small teeth, indicating the number of leaves which are joined together so as to form the cup or calyx.

These leaves are named (from Lat. _calyx_, a covering; Greek _kalyx_, from _kalyptein_, to cover) the calyx-leaves, or sepals (French _sépale_). Although they are united in the flower of the orange, they are often separate in other plants.

In the sacred Lotus or Padma or Pudma of India the sepals are separate or free. The leaves immediately inside the calyx are usually five in number. They are erect, or only slightly curved, and do not grow together like the leaves of the calyx. They are white and wax-like. These leaves form together what is termed the corolla, and the separate leaves of the corolla (from Lat. _corolla_, a little wreath) are termed petals (from Greek _petalon_, leaf). In the case of the orange the petals fall early away.

If the calyx and petals are carefully removed, the next part of the flower can be observed.

This series of flower-leaves differs very much in structure from both sepals and petals. Each leaf of this series consists of a linear stalk-like portion, bearing an upper somewhat long and grooved head. The stalk is named the filament, and the oblong head is named the anther (Greek _anthos_, a flower). The stalk and the head together form what is called the stamen (Lat. _stamen_, [Greek _histanai_, to stand] fibre; literally, the warp in the upright loom of the ancients). The stamens of the orange are rather shorter than the petals, and are united to each other.

When the anther is mature, each of its grooves splits near the edge, and allows the fine powdery granules which fill the anthers to be removed by insects or by other means. This fine powder is named the pollen, and each of the granules composing it is named a pollen grain. If the stamens are now removed the centre of the flower alone is left.

If the lower part of the centre of the flower be cut across, it will be found to be divided into a large number of cavities containing the minute rudiments of future seeds. It will be seen that there are ten cavities, though they may vary in number. The central organ of the flower is named the pistil (from Lat. _pistillum_, pestle). The pistil is usually composed of united leaves.

The separate leaves of the pistil are termed carpels (from Greek _karpos_, fruit). These leaves are sometimes not combined, as they are in the orange. The style belongs to the carpel, and varies considerably in length, as well as in stoutness, in different flowers. Although the carpels may be united, the styles may remain completely separate, as, for example, in the pink, or, as in the fuchsia, they may be combined into a single rod.

The pollen grains (Lat. fine flour) contained in the anther are composed of very rich protoplasm (Greek _protos_, first; _plasma_, formative matter), which usually has in it small drops of oil and small starch granules. The pollen grains are bounded by two principal layers, an outer and an inner; the purpose of the outer layer (which is often provided with thickenings in the shape of knots, spines, etc.) being to preserve the contents of the grain from evaporation.

The inner layer is living and capable of growth, and at certain spots it possesses thickenings which project into the protoplasm. Opposite to these the external cuticle is frequently thinner, and this eventually is lifted off as a sort of lid, and through this the inner substance can grow out, and is then named the pollen tube.

When the anther lobes open to discharge their pollen grains, these grains are completely developed.

The grains fall on the part of the ovary named the stigma (Greek _stigma_, a puncture made with a sharp instrument; here it means a sharp point or apex) and the inner layer begins to force its way out. The tube is produced from the contents of the pollen grain, and is formed by growth, just as any other part of the plant. The pollen tube passes down to the ovules, the route depending on the length of the style. The time taken by the pollen tube to reach the ovary may amount to a few hours in certain plants, while it needs months in others. It is necessary that at least one pollen tube should enter the mouth of the ovule before it can develop into a seed. The seed, when mature, contains the embryo plant.

It is not possible for an ovule in numerous cases to be fertilized by pollen from stamens that grow near it in the same flower.

It not unfrequently happens that a flower possesses stamens and no pistil, or a pistil and no stamens. Flowers of this kind are technically termed diœcious (Greek _dis_, twice, and _oikia_ or _oikos_, place of abode), if the male and female flowers are on different plants. The flowers of such plants as oaks and birches are male and female, but are borne on the same plant, hence termed monœcious (Greek _monos_, single). The flowers that contain stamens only are called male flowers, and those containing pistils only are named female flowers.

The oaks and birches, as has been stated, have both the male and female flowers on the same plant, though in other cases the male flower is borne on one plant and the female flower on another.

In cases like these the wind carries the pollen from one plant to another. In wind-fertilized flowers the flower is usually produced prior to the foliage leaves, or at least before the plant is crowded with leaves.

These plants produce an immense amount of pollen.

Besides the transference of pollen by the agency of the wind, insect agency plays a very important part. These insect-fertilized plants are much more conspicuous than those fertilized by the wind.

There are numerous natural contrivances in plants to prevent self-fertilization, as this process of self-fertilization is far less effective in producing seeds than when the ovules are fertilized by pollen from another plant of the same species.

In some plants the stigma is mature before the anther, and in such a case the pollen must be brought from a flower that has bloomed a little earlier than itself.

FLORA OF THE EARLY MESOZOIC
--SIR J. WILLIAM DAWSON

Great physical changes occurred at the close of the Carboniferous age. The thick beds of sediment that had been accumulating in long lines along the primitive continents had weighed down the earth’s crust. Slow subsidence had been proceeding from this cause in the coal-formation period, and at its close vast wrinklings occurred, only surpassed by those of the old Laurentian time. Hence in the Appalachian region of America we have the Carboniferous beds thrown into abrupt folds, their shales converted into hard slates, their sandstones into quartzite and their coals into anthracite, and all this before the deposition of the Triassic Red Sandstones which constitute the earliest deposit of the great succeeding Mesozoic period. In like manner the coal-fields of Wales and elsewhere in western Europe have suffered similar treatment, and apparently at the same time.

This folding is, however, on both sides of the Atlantic limited to a band on the margin of the continents, and to certain interior lines of pressure, while in the middle, as in Ohio and Illinois in America, and in the great interior plains of Europe, the coal-beds are undisturbed and unaltered. In connection with this we have an entire change in the physical character of the deposits, a great elevation of the borders of the continents, and probably a considerable deepening of the seas, leading to the establishment of general geographical conditions which still remain, though they have been temporarily modified by subsequent subsidences and re-elevations.

Along with this a great change was in progress in vegetable and animal life. The flora and fauna of the Palæozoic gradually die out in the Permian and are replaced in the succeeding Trias by those of the Mesozoic time. Throughout the Permian, however, the remains of the coal-formation flora continue to exist, and some forms, as the _Calamites_, even seem to gain in importance, as do also certain types of coniferous trees. The Triassic, as well as the Permian, was marked by physical disturbances, more especially by great volcanic eruptions discharging vast beds and dikes of lava, and layers of volcanic ash and agglomerate. This was the case more especially along the margins of the Atlantic, and probably also on those of the Pacific. The volcanic sheets and dikes associated with the Red Sandstones of Nova Scotia, Connecticut, and New Jersey are evidences of this.

At the close of the Permian and beginning of the Trias, in the midst of this transition time of physical disturbance, appear the great reptilian forms characteristic of the age of reptiles, and the earliest precursors of the mammals, and at this time the old Carboniferous forms of plants finally pass away, to be replaced by a flora scarcely more advanced, though different, and consisting of pines, cycads, and ferns, with gigantic equiseta, which are the successors of the genus _Calamites_, a genus which still survives in the early Trias. Of these groups the conifers, the ferns, and the equiseta are already familiar to us, and, in so far as they are concerned, a botanist who had studied the flora of the Carboniferous would have found himself at home in the succeeding period. The cycads are a new introduction. The whole, however, come within the limits of the cryptogams and the gymnosperms, so that here we have no advance.

As we ascend, however, in the Mesozoic, we find new and higher types. Even within the Jurassic epoch, the next in succession to the Trias, there are clear indications of the presence of the endogens, in species allied to the screw-pines and grasses; and the palms appear a little later, while a few exogenous trees have left their remains in the Lower Cretaceous, and in the Middle and Upper Cretaceous these higher plants come in abundantly and in generic forms still extant, so that the dawn of the modern flora belongs to the Middle and Upper Cretaceous. It will thus be convenient to confine ourselves in this chapter to the flora of the earlier Mesozoic.

Passing over for the present the cryptogamous plants already familiar in older deposits, we may notice the new features of gymnospermous and phænogamous life, as they present themselves in this earlier part of the great reptilian age, and as they extended themselves with remarkable uniformity in this period over all parts of the world. For it is a remarkable fact that, if we place together in our collections fossil plants of this period from Australia, India, China, Siberia, Europe, or even from Greenland, we find wonderfully little difference in their aspect. This uniformity prevailed in the Palæozoic flora; and it is perhaps equally marked in that of the Mesozoic. Still we must bear in mind that some of the plants of these periods, as the ferns and pines, for example, are still world-wide in their distribution; but this does not apply to others, more especially the cycads.

The cycads constitute a singular and exceptional type in the modern world, and are limited at present to the warmer climates, though very generally distributed in these, as they occur in Africa, India, Japan, Australia, Mexico, Florida, and the West Indies. In the Mesozoic age, however, they were world-wide in their distribution, and are found as far north as Greenland, though most of the species found in the Cretaceous of that country are of small size, and may have been of low growth, so that they may have been protected by the snows of winter. The cycads have usually simple or unbranching stems, pinnate leaves borne in a crown at top, and fruits which, though somewhat various in structure and arrangement, are all of the simpler form of gymnospermous type. The stems are exogenous in structure, but with slender wood and thick bark, and barred tissue, or properly as tissue intermediate between this and the disk-bearing fibres of the pines.

The greater part of the cycads of the Mesozoic age would seem to have had short stems and to have constituted the undergrowth of woods in which conifers attained to greater height. An interesting case of this is the celebrated dirt-bed of the quarries of the Isle of Portland, long ago described by Dean Buckland. In this fossil soil trunks of pines, which must have attained to great height, are interspersed with the short, thick stems of cycads, of the genus named _Cycadoidea_ by Buckland, and which from their appearance are called “fossil birds’ nests” by the quarrymen. Some, however, must have attained a considerable height so as to resemble palms.

The cycads, with their simple, thick trunks, usually marked with rhombic scars, and bearing broad spreading crowns of large, elegantly formed pinnate leaves, must have formed a prominent part of the vegetation of the Northern Hemisphere during the whole of the Mesozoic period. A botanist, had there been such a person at the time, would have found this to be the case everywhere from the equator to Spitzbergen, and probably in the Southern Hemisphere as well, and this throughout all the long periods from the Early Trias to the Middle Cretaceous. In a paper published in the _Linnæan Transactions_ for 1868, Dr. Carruthers enumerates twenty species of British Mesozoic cycads, and the number might now be considerably increased.

The pines present some features of interest. In the Mesozoic we have great numbers of beautiful trees, with those elegant fan-shaped leaves characteristic of but one living species, the _Salisburia_, or gingko-tree of China. It is curious that this tree, though now limited to eastern Asia, will grow, though it rarely fruits, in most parts of temperate Europe, and in America as far north as Montreal, and that in the Mesozoic period it occupied all these regions, and even Siberia and Greenland, and with many and diversified species.

_Salisburia_ belongs to the yews, but an equally curious fact applies to the cypresses. The genus _Sequoia_, limited at present to two species, both Californian, and one of them the so-called “big tree,” celebrated for the gigantic size to which it attains, is represented by species found as far back at least as the Lower Cretaceous, and in every part of the Northern Hemisphere.[1] It seems to have thriven in all these regions throughout the Mesozoic and early Kainozoic, and then to have disappeared, leaving only a small remnant to represent it in modern days. A number of species have been described from the Mesozoic and Tertiary, all of them closely related to those now existing.

The name itself deserves consideration. It is that of an Indian of the Cherokee tribe, Sequo Yah, who invented an alphabet without any aid from the outside world of culture, and taught it to his tribe by writing it upon leaves. This came into general use among the Cherokees before the white man had any knowledge of it; and afterward, in 1828, a periodical was published in this character by the missionaries. Sequo Yah was banished from his home in Alabama, with the rest of his tribe, and settled in New Mexico, where he died in 1843.

When Endlicher was preparing his synopsis of the conifers, in 1846, and had established a number of new genera, Dr. Jacbon Tschudi, then living with Endlicher, brought before his notice this remarkable man, and asked him to dedicate this red-wooded tree to the memory of a literary genius so conspicuous among the red men of America. Endlicher consented to do so, and only endeavored to make the name pronounceable by changing two of its letters.

Endlicher founded the genus on the redwood of the Americans, _Taxodium sempervirens_ of Lamb; and named the species _Sequoia sempervirens_. These trees form large forests in California, which extend along the coast as far as Oregon. Trees are there met with of 300 feet in height and 20 feet in diameter. The seeds were brought to Europe a number of years ago, and we already see in upper Italy and around the Lake of Geneva, and in England, high trees; but, on the other hand, they have not proved successful around Zurich.

In 1852, a second species of Sequoia was discovered in California, which, under the name of big tree, soon attained a considerable celebrity. Lindley described it, in 1853, as _Wellingtonia gigantea_; and, in the following year, Decaisne and Torrey proved that it belonged to Sequoia, and that it accordingly should be called _Sequoia gigantea_.

While the _Sequoia sempervirens_, in spite of the destructiveness of the American lumbermen, still forms large forests along the coasts, the _Sequoia gigantea_ is confined to the isolated clumps which are met with inland at a height of 5,000 to 7,000 feet above sea-level, and are much sought after by tourists as one of the wonders of the country. Reports came to Europe concerning the largest of them which were quite fabulous, but we have received accurate accounts of them from Professor Whitney. The tallest tree measured by him has a height of 325 feet, and in the case of one of the trees the number of the rings of growth indicated an age of about 1,300 years. It had a girth of 50 to 60 feet.

We know only two living species of _Sequoia_, both of which are confined to California. The one (_S. sempervirens_) is clothed with erect leaves, arranged in two rows, very much like our yew-tree, and bears small, round cones; the other (_S. gigantea_) has smaller leaves, set closely against the branches, giving the tree more the appearance of the cypress. The cones are egg-shaped, and much larger. These two types are, therefore, sharply defined.

Both of these trees have an interesting history. If we go back into the Tertiary, this same genus meets us with a long array of species. Two of these species correspond to those living at present: the _S. Langsdorfii_ to the _S. sempervirens_, and the _S. Couttsiæ_ to the _S. gigantea_. But, while the living species are confined to California, in the Tertiary they are spread over several quarters of the globe.

Let us first consider the _Sequoia Langsdorfii_. This was first discovered in the lignite of Wetterau, and was described as _Taxites Langsdorfii_. Heer found it in the upper Rhone district, and there lay beside the twigs the remains of a cone, which showed that the _Taxites Langsdorfii_ of Brongniart belonged to the Californian genus _Sequoia_ established by Endlicher. He afterward found much better preserved cones, together with seeds, along with the plants of east Greenland, which fully confirmed the determination. At Atanekerdluk in Greenland (about 70° north latitude) this tree is very common. The leaves, and also the flowers and numerous cones, leave no doubt that it stands very near to the modern redwood. It differs from it, however, in having a much larger number of scales in the cone. The tree is also found in Spitzbergen at nearly 78° north latitude, where Nordenskiöld has collected, at Cape Lyell, wonderfully preserved branches. From this high latitude the species can be followed down through the whole of Europe as far as the middle of Italy (at Senegaglia, Gulf of Spezia). In Asia, also, we can follow it to the steppes of Kirghisen, to Possiet, and to the coast of the sea of Japan, and across to Alaska and Sitka. It is recognized by Mr. Starkie Gardner as one of the species found in the Eocene of Mull in the Hebrides. It is thus known in Europe, Asia, and America from 43° to 78° north latitude, while its most nearly related living species, perhaps even descended from it, is now confined to California.

With this _S. Langsdorfii_, three other Tertiary species are nearly related (_S. brevifolia_, Hr., _S. disticha_, Hr., and _S. Nordenskiöldi_, Hr.). These have been met with in Greenland and Spitzbergen and one of them has been found in the United States. Three other species, in addition to these, have been described by Lesquereux, which appear to belong to the group of the _S. Langsdorfii_, viz., _S. longifolia_, Lesq., _S. angustifolia_, and _S. acuminata_, Lesq. Several species also occur in the Cretaceous and Eocene of Canada.

These species thus answer to the living _Sequoia sempervirens_; but we can also point to Tertiary representatives of the _S. gigantea_. Their leaves are stiff and sharp-pointed, are thinly set round the branches, and lie forward in the same way: the egg-shaped cones are in some cases similar.

There are, however, in the early Tertiary six species, which fill up the gap between _S. sempervirens_ and _S. gigantea_. They are the _S. Couttsiæ_, _S. affinis_, Lesq., _S. imbricata_, Hr., _S. sibirica_, Hr., _S. Heerii_, Lesq., and _S. biformis_, Lesq. Of these, _S. Couttsiæ_, Hr., is the most common and most important species. It has short leaves, lying along the branch, like _S. gigantea_, and small, round cones, like _S. Langsdorfii_ and _sempervirens_. Bovey Tracey in Devonshire has afforded splendid specimens of cones, seeds, and twigs, which have been described in the _Philosophical Transactions_. More lately, Count Saporta has described specimens of cones and twigs from Armissan. Specimens of this species have also been found in the older Tertiary of Greenland, so that it must have had a wide range. It is very like to the American _S. affinis_, Lesq.

In the Tertiary there have been found fourteen well-marked species, which thus include representatives of the two living types, _S. sempervirens_ and _S. gigantea_.

We can follow this genus still further back. If we go back to the Cretaceous age, we find ten species, of which five occur in the Urgon of the Lower Cretaceous, two in the Middle, and three in the Upper Cretaceous. Among these, the Lower Cretaceous exhibits the two types of the _Sequoia sempervirens_ and _S. gigantea_. To the former the _S. Smithiana_ answers, and to the latter, the _Reichenbachii_, Gein. The _S. Smithiana_ stands indeed uncommonly near the _S. Langsdorfii_, both in the appearance of the leaves on the twigs and in the shape of the cones. These are, however, smaller, and the leaves do not become narrower toward the base. The _S. pectina_, Hr., of the Upper Cretaceous, has its leaves arranged in two rows, and presents a similar appearance. The _S. Reichenbachii_ is a type more distinct from those now living and those in the Tertiary. It has indeed stiff, pointed leaves, lying forward, but they are arcuate, and the cones are smaller. This tree has been known for a long time, and it serves in the Cretaceous as a guiding star, which we can follow from the Urgonian of the Lower Cretaceous up to the Cenomanian. It is known in France, Belgium, Bohemia, Saxony, Greenland, and Spitzbergen (also in Canada and the United States). It has been placed in another genus--Geinitzia--but we can recognize, by the help of the cones, that it belongs to Sequoia.

Below this, there is found in Greenland a nearly related species, the _S. ambigua_, Hr., of which the leaves are shorter and broader, and the cones round and somewhat smaller.

The connecting link between _S. Smithiana_ and _Reichenbachii_ is formed by _S. subulata_, Hr., and _S. rigida_, Hr., and three species (_S. gracilis_, Hr., _S. fastigiata_ and _S. Gardneriana_, Carr.), with leaves lying closely along the branch, and which come very near to the Tertiary species _S. Couttsiæ_. We have, therefore, in the Cretaceous quite an array of species, which fill up the gap between the _S. sempervirens_ and _gigantea_, and show us that the genus Sequoia had already attained a great development in the Cretaceous. This was still greater in the Tertiary, in which it also reached its maximum of geographical distribution. Into the present world the two extremes of the genus have alone continued; the numerous species forming its main body have fallen out in the Tertiary.

If we look still further back, we find in the Jura a great number of conifers, and, among them, we meet in the genus Pinus with a type which is highly developed, and which still survives; but for Sequoia we have till now looked in vain, so that for the present we can not place the rise of the genus lower than the Urgonian of the Cretaceous, however remarkable we may think it that in that period it should have developed into so many species; and it is still more surprising that two species already make their appearance which approach so near to the living _Sequoia sempervirens_ and _S. gigantea_.

Altogether, we have become acquainted, up to the present time, with twenty-six species of Sequoia. Fourteen of these species are found in the Arctic zone, and have been described and figured in the _Fossil Flora of the Arctic Regions_. Sequoia has been recognized by Ettingshausen even in Australia, but there in the Eocene.

This is, perhaps, the most remarkable record in the whole history of vegetation. The Sequoias are the giants of the conifers, the grandest representatives of the family; and the fact that, after spreading over the whole Northern Hemisphere and attaining to more than twenty specific forms, their decaying remnant should now be confined to one limited region in western America[2] and to two species constitutes a sad memento of departed greatness. The small remnant of _S. gigantea_ still, however, towers above all competitors as eminently the “big trees”; but, had they and the allied species failed to escape the Tertiary continental submergences and the disasters of the glacial period, this grand genus would have been to us an extinct type. In like manner the survival of the single gingko of eastern Asia alone enables us to understand that great series of taxine trees with fern-like leaves of which it is the sole representative.

Besides these peculiar and now rare forms, we have in the Mesozoic many others related closely to existing yews, cypresses, pines, and spruces, so that the conifers were probably in greater abundance and variety than they are at this day.

In this period also we find the earliest representatives of the endogenous plants. It is true that some plants found in the coal-formation have been doubtfully referred to these, but the earliest certain examples would seem to be some bamboo-like and screw-pine-like plants occurring in the Jurassic rocks. Some of these are, it is true, doubtful forms, but of others there seems to be no question. The modern _Pandanus_ or screw-pine of the tropical regions, which is not a pine, however, but a humble relation of the palms, is a stiffly branching tree, of a candelabra-like form, and with tufts of long leaves on its branches, and nuts or great hard berries for fruit, borne sometimes in larger masses, and so protected as to admit of their drifting uninjured on the sea. The stems are supported by masses of aerial roots like those which strengthen the stems of tree-ferns. These structures and habits of growth fit the Pandanus for its especial habitat on the shores of tropical islands, where its masses of nuts are drifted by the winds and currents, and on whose shores it can establish itself by the aid of its aerial roots.

Some plants referred to the cycads have proved veritable botanical puzzles. One of these, the _Williamsonia gigas_ of the English oölite, originally discovered by my friend, Dr. Williamson, and named by him _Zamia gigas_, a very tall and beautiful species, found in rocks of this age in various parts of Europe, has been claimed by Saporta for the Endogens, as a plant allied to _Pandanus_. Some other botanists have supposed the flowers and fruits to be parasites on other plants, like the modern _Rafflesia_ of Sumatra, but it is possible that after all it may prove to have been an aberrant cycad.

The tree-palms are not found earlier than the Middle Cretaceous. In like manner, though a few Angiosperms occur in rocks believed to be Lower or Lower Middle Cretaceous in Greenland and the Northwest Territory of Canada, and in Virginia, these are merely precursors of those of the Upper Cretaceous, and are not sufficient to redeem the earlier Cretaceous from being a period of pines and cycads.

On the whole, this early Mesozoic flora, so far as known to us, has a monotonous and mean appearance. It no doubt formed vast forests of tall pines, perhaps resembling the giant Sequoias of California; but they must for the most part have been dark and dismal woods, probably tenanted by few forms of life, for the great reptiles of this age must have preferred the open and sunny coasts, and many of them dwelt in the waters. Still we must not be too sure of this. The berries and nuts of the numerous yews and cycads were capable of affording much food. We know that in this age there were many great herbivorous reptiles, like _Iguanodon_ and _Hadrosaurus_, some of them fitted by their structure to feed upon the leaves and fruits of trees. There were also several kinds of small herbivorous mammals, and much insect life, and it is likely that few of the inhabitants of the Mesozoic woods have been preserved as fossils. We may yet have much to learn of the inhabitants of these forests of ferns, cycads, and pines. We must not forget in this connection that in the present day there are large islands, like New Zealand, destitute of mammalia, and having a flora comparable with that of the Mesozoic in the Northern Hemisphere, though more varied. We have also the remarkable example of Australia, with a much richer flora than that of the early Mesozoic, yet inhabited only by non-placental mammals, like those of the Mesozoic.

The principal legacy that the Mesozoic woods have handed down to our time is in some beds of coal, locally important, but of far less extent than those of the Carboniferous period. Still, in America, the Richmond coal-field in Virginia is of this age, and so are the anthracite beds of the Queen Charlotte Islands, on the west coast of Canada, and the coal of Brora in Sutherlandshire. Valuable beds of coal, probably of this age, also exist in China, India, and South Africa; and jet, which is so extensively used for ornament, is principally derived from the carbonized remains of the old Mesozoic pines.

EXISTING LIFE-FORMS OF PLANTS
--EDWARD CLODD

Plants are divided into two main groups or sub-kingdoms: I, _Cryptogams_ (Greek _Kruptos_, hidden; _gamos_, marriage), or flowerless; II, _Phanerogams_ (Greek _phaneros_, open; _gamos_, marriage), or flowering.

I. The _Cryptogams_ comprise as their leading representatives: 1. Algæ, Fungi, Lichens; 2. Liverworts, Mosses; 3. Ferns, Horsetails, Club-mosses.

The feature common to these is the absence of any conspicuous organs; _i. e._, true flowers with stamens and pistils for the production of seeds or fruits. The simplest or single-celled plants increase by subdivision, each cell carrying on an independent life and repeating the process of division. But sexuality is manifest in plants very low down in the scale, the mode of reproduction varying a good deal in different species. In some cryptogams it is almost as complex as in the flowering plants, but notwithstanding the different kinds of sexual organs, there is this fundamental resemblance between them, that the union of the contents of two cells, a male or sperm-cell, and a female or germ-cell, each of which is by itself incapable of further development, is essential to the production of the embryo or seed.

The lowest cryptogams have no stems, leaves, or roots. They are congregations of simple fibreless cells united in rows, or gathered round one another, spreading on all sides. At the bottom of the scale of plant life are the _Algæ_, comprising some 10,000 species, from the minute fresh-water desmids, one-millionth of an inch in length, with their whip-like cilia, the two-hundredth millionth of an inch long, to the giant sea-weeds or tangles, hundreds of feet in length, that cover thousands of square miles of ocean. The green scum of stagnant ponds; the waving filaments in streams; the shell-coated microscopic diatoms that people the ocean, tingeing its depths with olive green, nourishing the whales that play therein, and whose skeletons form deposits hundreds of miles in length; the rose and purple weeds that flourish in shallow seas, and are cast upon their shores, are all members of a group which is perhaps the venerablest of living things. For although their generally fragile forms have been fatal to their preservation as fossils, there is little doubt that the algæ flourished in dense masses in primeval oceans, and were the chief, if not the sole, representatives of plant-life on the earth during millions of centuries. Like the foraminifera and other low animal organisms, they illustrate the persistency of the earlier forms, in virtue of their simplicity of structure, despite changing conditions, whereas the more complex structures, by reason of the greater delicacy of their parts, can less readily adapt themselves to altered surroundings, and therefore have a much narrower distribution both in time and space.

Next to the algæ in ascending order are those fantastic products of decay, the quick-growing, short-lived _Fungi_, animal-like in their mode of nutrition, plant-like in their fixity; then the _Lichens_, which, it is now generally agreed, are composite plants, being a special kind of parasite fungi growing on algæ. These are widely spread, living after the adaptive manner of simple forms, where nothing else can live, unwithered by the heat, unsmitten by the frost; redeeming the earth’s desolate places, from treeless desert flats far as the lines of enduring snow; spreading their flowerless patches of richest colors in metallic-like stain over rock and ruin; incrusting the trees with tint of freshness or touch of age, with hoary fringe or mock hieroglyph; and in their decay yielding rich soil wherein fern and flowering tree may strike root.

In the _Mosses_, whose glossy, many-colored masses weave softest carpet over the earth, sharing in the service rendered by the humble lichens, the cells have become more developed into rudimentary root, stem, and leaf, manifesting still further transition toward unlikeness in parts due to division of function. But the structure is still cellular--_i. e._, there are no tissues and fibres. The mosses represent the intermediate form between the lowest and the highest cryptogams, between the green algæ--out of which the liverworts were probably developed--and the ferns, which arose out of liverworts.

In the _Ferns_, the larger number of cells have joined together to form fibrous vessels, lengthening of thickening in varying shape and texture, according to the functions to be discharged by them, resulting in the woody tissue which enters into the structure of all the higher plants. The cells which are thus converted into tissue cease to grow; the formative protoplasm becomes the formed, having given up its life for the plant, and locked up in the compacted material a store of energy for service both within the plant and by the agency of the plant. The ferns and club-mosses and horsetails of the present day are the dwarfed representatives of the stately and luxuriant, although sombre, flowerless trees that composed the dense jungles of green vegetation in the _Devonian_ and succeeding _Primary_ periods. These are distinguished as the Era of Fern Forests, during which our fossil fuel was chiefly formed; and although the palm-like vegetation of the tropics more nearly approaches its _Devonian_ prototype, it falls far behind it in size and abundance.

II. The _Phanerogams_ have their flowers with stamens and pistils conspicuous, and are divided, according to the formation of their seeds, into:

1. _Gymnosperms_, or naked-seeded, the ovules not being inclosed within a seed-vessel or ovary, but carried upon a cone, as in pines and allied species.

2. _Angiosperms_, or cover-seeded, the ovules being inclosed within an ovary.

This group is subdivided into (_a_) plants having one seed-leaf from which they are developed, as palms, lilies, orchids, grasses; and into (_b_) plants having two seed-leaves, as oaks, beeches, and all trees and shrubs not included in the foregoing species.

In naked-seeded plants the pollen or male element falls on the exposed ovules; in cover-seeded plants it falls on the stigma, passes down the pistil into the seed-vessel, and enters the ovule through an opening in it called the microphyle, or “little gate.”

While the gymnosperms are, on the one hand, most nearly allied in the order of descent to ferns, the sombre flowers which they bear giving them, only by strict botanical classification, a place among phanerogams, they are, on the other hand, more complex in structure than the single seed-leaf plants, because their bark, wood, and pith are clearly defined, as in the double seed-leaf plants. Their lowest representatives comprise the cycads or palm-ferns, so called from their resemblance to palms, for which, with their crown of feathery leaves, they are often mistaken. Next in order is the much more varied and widely distributed conifer family, notably pines, firs, and larches, and, lesser in importance, cedars and cypresses. A still higher class, various in its modes of growth, marks the transition, to angiosperms, the flowers of both having many features in common.

The single seed-leaf angiosperms have no visible separation of their woody stuff into bark, stem, and pith, and have no rings of growth, the wood exhibiting an even surface, dotted over with small dark points. Their leaves have parallel veins or “nerves,” as in the onion and tulip, and the blossom-leaves, or petals, are grouped in threes or multiples of three. Among their several representatives we may single out the lilies for their beauty and fragrance, and the cereals for their value and importance, both classes being in near connection, since the grasses from which man has developed wheat, barley, oats, rice, and maize are, in a botanical sense, degenerate descendants of the lily family.