Chapter III: Front Matter (3)

Some few of the _Chlorospermeæ_ are large and conspicuous organisms. Such, _e.g._, is _Caulerpa_, which abounds on warm, sandy coasts, and on which turtles browse. Though, as we shall hereafter see, it is really as simple in structure as a particle of yeast, it yet presents a very complicated external figure.

Some of the great group of _Algæ_ attain enormous dimensions. Thus, _Macrocystis_ (one of the _Melanospermæ_), of the Southern Ocean, may be even 700 feet in length. Another kind, _Lessonia_, forms submarine forests, with stems like the trunks of trees.

The group of _Floridiæ_ includes the delicate and elegant sea-weeds, which are amongst the most admired vegetable productions of our coasts. They are of interest, on account of various peculiarities in their reproductive processes.

Other lowly plants may, at least provisionally, be placed in the great group to which mushrooms and truffles belong--the group of _Fungi_--a group the members of which agree in certain exceptional phenomena of function,[20] as well as of structure and composition--as they are exceptionally nitrogenous.

Amongst the lowest which we may for convenience provisionally include in this group may be mentioned minute _Vibrios_, such as the _Bacteria_ so much talked of in connexion with spontaneous generation, and the small plant which by its growth produces fermentation--the yeast-plant (_Saccharomyces_).[21] Closely allied to the yeast-plant are the "moulds" which grow on organic matters such as _Penicillium_, _Mucor_, _Saprolegna_, _Phytophthora_, the last of which is the potato disease.

A singular group of organisms goes by the name of _Myxomycetes_. These enigmatical creatures have been classed in turn as animals and as plants, and, indeed, at one period of their existence they seem to have more resemblance to the former, while at another stage of their life history they must unquestionably be ranked as plants. When young, they are in a semi-fluid condition, and so move that they seem, as it were, to flow over the body on which they rest. They grow upon the bark of trees or on leaves and decayed wood. They exhibit movements like those of the amæbæ and are said to engulph nutritious matters which come in their way.

The dry-looking, green, grey, red or yellow vegetable structures which encrust our rocks, walls, and trees, and which are called _Lichens_, form a group of plants curiously intermediate between Fungi and _Algæ_.

Plants somewhat higher in the scale of vegetable life are those which are termed liverworts (_Hepaticæ_), including the scale-mosses (_Jungermanniaceæ_) and _Marchantia_. These plants, as we shall see, are interesting on account of the variations to be found in the forms of different genera. In many, there is no stem, but only a connected series of green disk-like expansions, while others have a distinct stem with leaf-like outgrowths.

Two genera of aquatic plants (_Chara_ and _Nitella_) constitute another group of plants called _Characeæ_. These will be hereafter referred to both on account of peculiarities in their structure and on account of a peculiar motion of protoplasm which is easily to be seen[22] in them.

Mosses (_Musci_) are familiar objects to every one in this country, and allied to them are the so-called "club-mosses" or _Lycopods_, which form a sort of green sward in so many parts of the warmer regions of the earth. To one of the lycopods, called _Selaginella_, reference will hereafter be made in connexion with its very instructive reproductive process.

Certain humble plants, in some of which the foliage leaves present a superficial resemblance to those of a four-leaved clover, are popularly called pepperworts; by botanists, _Rhizocarpeæ_ or _Marsiliaceæ_. They are creeping or floating stemless plants which inhabit ditches or inundated places. They are scattered over both the Old and New Worlds, but are chiefly found in temperate latitudes.

The horse-tails (_Equisetaceæ_) are also found in most parts of the world, though wanting in Australia and New Zealand. They inhabit wet and sandy places, and sometimes are of a considerable size even in the present day, but in ancient geological periods they attained the proportions of trees.

This group leads us on to their allies the ferns which form a very large natural group _Filices_ or _Pteridophytes_--a group now familiar to every one interested in plants. Common as ferns are in our own country, they are far more abundant and attain to a much greater size in southern latitudes--notably in New Zealand and various Pacific islands.

All the plants hitherto enumerated, from the protococcus to the tree-ferns inclusive, together form what is commonly regarded as one great primary division or "sub-kingdom" of vegetals called CRYPTOGAMIA. In no plant belonging to this sub-kingdom--in no single cryptogam--is any flower ever developed. These form the great group which is often spoken of as "flowerless plants."

The other primary division of vegetable organisms consists of all plants with flowers, and is termed PHANEROGAMIA, and is subdivided into two sections,[23] very unequally numerous. To the first section of phanerogams--a section containing comparatively few kinds--belong all firs, pines, yews, junipers, araucarias, and a most remarkable African plant, _Welwitschia_, which has never more than two leaves, though these attain enormous dimensions. All these plants are collectively spoken of as conifers, or _Coniferæ_. Besides these, certain curious southern forms called Cycads are also associated in this section. To this section, thus composed of conifers and cycads, the name GYMNOSPERMS is given, from the naked mode of development of their young seeds. These gymnosperms are also characterized by having such peculiar and inconspicuous flowers that the ordinary observer would hardly apply that term to denote their floral organs.

All the plants which yet remain to be noticed, and which belong to the second and very much larger section of the PHANEROGAMIA are spoken of as _Angiosperms_. Their seeds are, from their first appearance, in a very different condition from those of gymnosperms, and their flowers are generally conspicuous. To this group, therefore, belong all the familiar ornamental plants of our gardens, and all the brightly coloured natural ornaments of our fields, as well as a number of herbs and trees, the flowers of which, though truly flowers, are not commonly recognized as such.

This group of Angiospermous flowering plants is divided into a great number of natural groups or "orders." Of these there are about 275, and they are grouped in two sets or classes, which are separated one from another, as we shall hereafter see, by differences as to their modes of growth, the structure of their seeds, the numbers of the parts of their flowers, and the course of the veins in their leaves.

First amongst the Angiospermous flowering plants may be mentioned the grasses forming the order _Gramineæ_, including under that term the tree-like bamboos (of multitudinous uses), with the rice plant, and all the grain-bearing herbs, all of which are grasses. Thus, with much reason may it be said of man, that "all flesh is grass;" for with the exception of the piscivorous Esquimaux, the exclusively flesh-eating Gouchos, the population of Australia, and the people of the Molluccas who nourish themselves on sago--which is the produce of a palm--with these and a few more exceptions, the staple food of the human race is one or another form of grass. It is, indeed, a remarkable fact that men of such varied races so widely spread should have thus selected as their food objects so little tempting in appearance, and so small and so inconspicuous as the seeds of grasses!

Allied to the grasses are the sedges (forming the order _Cyperaceæ_), and the rushes (_Juncaceæ_). The apparently insignificant, but really interesting duckweeds (_Pistiaceæ_) should also be noted with the bullrushes (_Typheæ_), and the arums (_Aroideæ_). This last-mentioned order, familiar to us by the kind known as "Lords and Ladies," presents some climbing forms in tropical countries. Generally acrid, some species, when in flower, even produce headache and vomiting; at least an explorer was attacked with these symptoms after gathering forty specimens of _Arum dracunculus_. The order is also interesting from experiments as to vegetable heat, which have been made with the flowers of some of its species.

The screw-pines (_Pandanaceæ_) are not "pines" at all, any more than "pine-apples" are pines. They are, indeed, trees or shrubs, which, from one point of view, may be regarded as gigantic bulrushes. The flowers of certain species are in some places eaten as the solid equivalent of a love potion. Allied to the plants of the last-mentioned order are the palms (_Palmaceæ_), which are the first really large trees we come to after leaving the tree-ferns and the gymnosperms. Amongst the more noteworthy palms may be mentioned the palmetto (_Chamærops_) of Southern Europe (a summer ornament of our public gardens), the date palm, the areca palm, the sago palm, the cocoa palm, the rattan palm--a natural cordage--and _Seaforthia_, so remarkable for its graceful and elegant form.

Next may be enumerated the great order of lilies (_Liliaceæ_), to which the homely and useful onion, leek, garlic, chive, and asparagus belong, no less than a multitude of lovely flowers.

The New Zealand flax (_Phormium tenax_), and all the magnificent yuccas and aloes, together with our English butcher's broom (_Ruscus aculeatus_), which has not a little botanical interest (as being the only British shrub which belongs to the group called "Monocotyledons") also belong to this order. Closely allied to the lilies are the amaryllids (_Amaryllidaceæ_), amongst which are the agaves, with their gigantic flower stems, sometimes forty feet high, supporting a multitudinous crop of flowers, the product and termination of a life.

To these follow the pine-apples (_Bromeliaceæ_) all originally from America, the useful bananas and plantains (_Musaceæ_), and the ginger-plants (_Zingiberaceæ_), tropical herbs, generally of great beauty.

The underground parts of certain tropical plants (_Dioscoreaceæ_) are known as "yams." A representative of this order exists in England in the climbing black bryony (_Tamus_) of our hedges, and to the same group belongs the very singularly stemmed elephant's foot, or tortoise-tree (_Testudinaria elephantipes_). The last-named plant is a native of the Cape of Good Hope, where it has been known as Hottentot's bread, because the soft interior of its swollen base was at one time eaten by the natives of that region, who have, however, now abandoned it to the baboons.

Lastly, in this connexion may be mentioned the very interesting and beautiful group of orchids (_Orchidaceæ_), many of which live high up in the air, supported on the branches of trees, from which their roots hang freely down. Such orchids are sometimes spoken of as "air-plants."

All the Angiosperms as yet mentioned, from the grasses to the orchids inclusively, belong to the lower of the two great groups or classes into which, as was lately said, the whole mass of Angiosperms is divided.

This great group is named _Monocotyledones_ (on account of the structure of the seed), and it is sometimes spoken of as _Endogens_, in reference to a generally prevalent habit of growth. The members of this whole class will then hereinafter be spoken of as "Monocotyledons."

All the plants which yet remain to be enumerated belong to the other and still greater group of Angiosperms called (also in reference to their seeds) _Dicotyledons_, a group sometimes spoken of as "_Exogens_," in reference to the habit of growth prevalent amongst its species.

All our familiar trees which are not conifers, and most of our flowering shrubs and herbs, are "Dicotyledons."

Amongst the many orders which compose the Dicotyledonous group the few following may be selected for enumeration, either on account of the general interest they possess, or because they will have to be more or less referred to hereafter.

We may thus note the singular order of vegetable parasites, the _Loranthaceæ_, an order containing some thirty genera with four hundred species, and including the mistletoe, which is traditionally venerable in our island. The great group of catkin-bearing trees (_Amentaceæ_), contains a great assemblage of plants, familiar in England, such as the hornbeam, hazel, oak, beech, Spanish chestnut, birch, willow, poplar, &c.[24]

The largest and one of the most remarkable flowers in the world, _Rafflesia_--a parasite found in Java and Sumatra by Sir Stamford Raffles--is the type of the small order _Rafflesiaceæ_. The eccentric pitcher-bearing plants form the order _Nepenthaceæ_. The English herb called "Spurge" (with its milky juice), belongs to the order (_Euphorbiaceæ_), which is a large[25] cosmopolitan group, some species of the plants belonging to which attain, in hot countries, the size of trees. Certain African species strangely resemble different kinds of _Cactus_. The elm order (_Ulmaceæ_) may come next. The hop, the hemp, the mulberry, the fig, and the dorstenia are all nearly allied, the first two belonging to the order _Cannabinaceæ_, the last three to the _Moraceæ_. The bread-fruit of the South-Sea Islands belongs to the same order (_Artocarpaceæ_) as does the deadly upas-tree of Java. Garments made of the inner bark of this plant are like the shirt of Nessus, and will produce intolerable irritation; and even climbing the tree to obtain its flowers is said to have produced severe effects on the climber. In proximity to the last-mentioned plant comes appropriately (as also in its proper botanical order) the group of stinging-nettles (_Urticaceæ_). The curious Australian plants which delighted the eyes of Captain Cook's botanical companions belong to the order _Proteaceæ_. Besides these may be mentioned the dead-nettle order (_Labiatæ_); the broom-rapes (_Orobanchaceæ_); the order of snap-dragons and foxgloves (_Scrophularineæ_); the potato group (_Solanaceæ_), which includes the deadly nightshade and the dulcamara of our hedges; the parasitic order (_Cuscutaceæ_); the beautiful group of convolvuluses (_Convolvulaceæ_); the gentians (_Gentianaceæ_); the primrose group (_Primulaceæ_); the heaths (_Ericaceæ_); the graceful hair-bell and its allies (_Campanulaceæ_); the very large group to which belong the daisy, dandelion, and thistle (_Compositæ_); the honeysuckle order (_Caprifoliaceæ_); the ivy (_Araliaceæ_); the large order containing the fennel, hemlock, and a multitude of other forms which, though mostly ranking as herbs, attain gigantic dimensions in some species found in Africa and Kamskatka (_Umbelliferæ_); the very singularly-shaped group of cactuses (_Cactaceæ_), with leafless fleshy stems, which sometimes look like dry columns and sometimes are globular; the begonias (_Begoniaceæ_); the cucumbers, melons, and vegetable marrows (_Cucurbitaceæ_); the singularly-formed passion-flowers (_Passifloraceæ_); the myrtles (_Myrtaceæ_); the carnivorous group containing the sundew and Venus's flytrap (_Droseracæ_); the fleshy houseleek and stonecrops (_Crassulaceæ_); the Saxifrages (_Saxifragaceæ_); the rose group (_Rosaceæ_), which includes within it most of our fruits, such as the apple, pear, strawberry, cherry, peach, plum, almond, and others; the very large order which contains the peas, beans, and their allies (_Leguminoseæ_); the horse-chestnut order (_Hippocastaneæ_); the maples (_Acerineæ_); the hollies (_Ilicineæ_); the oranges and citrons (_Aurantiaceæ_); the cranesbills and pelargoniums (_Geraniaceæ_); the flaxes (_Linaceæ_); the limes (_Tiliaceæ_), in which the useful jute is included; the mallows (_Malvaceæ_); the St. John's worts (_Hypericaceæ_); the order of pinks (_Caryophylleæ_); the pansies (_Violaceæ_); the rock-roses (_Cistaceæ_); the mignonette group (_Resedaceæ_); the great wall-flower and cabbage group (_Cruciferæ_); the poppies (_Papaveraceæ_); the water-lilies (_Nymphaceæ_); the berberries (_Berberideæ_); the custard-apples (_Anonaceæ_); the magnolias (_Magnoliaceæ_); and, finally, the great group (_Ranunculaceæ_) containing the anemones, the clematis, hellebore, monkshood, and the buttercup, which last is of great use to the student of Botany because it is an excellent type of all flowers.

The above may serve as a brief enumeration of the more generally known or more interesting orders of flowering plants, as also of the most noteworthy forms of cryptogams. The much more numerous and complex groups of animals have also been catalogued in the earlier and larger part of this Essay, which may thus, it is hoped, answer the purpose of an introduction to those multitudinous forms of organic life, the leading points in the structure and functions of which are hereafter to occupy us.

The main groups of Animals and Plants may be provisionally tabulated as follows:--

ANIMALS.

{ _Mammalia_ (Man and Beasts)
(1) VERTEBRATA { _Aves_ (Birds)
(Back-boned { _Reptilia_ (Serpents, Crocodiles, Lizards, &c.)
Animals) { _Batrachia_ (Frogs, Efts, &c.)
{ _Pisces_ (Fishes)

{ _Cephalopoda_ (Cuttle Fishes)
(2) MOLLUSCA { _Pteropoda_
(Soft Animals) { _Gasteropoda_ (Snails, &c.)
{ _Lamellibranchiata_ (Oysters, &c.)
{ _Brachiopoda_ (Lamp-shells)

(3) TUNICATA (Ascidians, Tunicaries, or Sea-squirts)

(4) ARTHROPODA { _Crustacea_ (Crabs, &c.)
(Animals with { _Myriapoda_ (Hundred-legs, &c.)
jointed feet) { _Arachnida_ (Scorpions, Spiders, &c.)
{ _Insecta_

{ _Annelida_ (Earth-worms, Leeches, &c.)
{ _Enteropneusta_ (Balanoglossus)
{ _Bryozoa_ (Sea-mat, &c.)
{ _Nematoidea_ (Thread-worms)
(5) VERMES { _Trematoda_ (Flukes, &c.)
{ _Turbellaria_ (Planariæ, &c.)
{ _Cestoidea_ (Tape-worms)
{ _Rotifera_ (Wheel-animalcules)
{ _Gasterotricha_
{ _Gephyrea_ (Sipunculus, &c.)

(6) ECHINODERMA (Star-fishes, &c.)

{ _Ctenophora_ (Beröe, &c.)
(7) COELENTERA { _Actinozoa_ (Coral animals)
{ _Hydrozoa_ (Jelly-fishes, &c.)

(8) SPONGIDA (Sponges)

{ _Infusoria_ (Animalcules with mouths)
(9) HYPOZOA { _Gregarinida_
{ _Rhizopoda_ (Foraminifers, Radiolarians,
Flagellata, &c.)

PLANTS.

{ _Algæ_ (Sea-weeds, Confervæ, &c.)
{ _Fungi_
{ _Lichenes_
(1) CRYPTOGAMIA { _Hepaticæ_ (Liverworts and Scale-mosses)
(Flowerless { _Characeæ_ (Nitella, &c.)
Plants) { _Musci_ (Mosses)
{ _Marsiliaceæ_ (Pepperworts)
{ _Equisetaceæ_ (Horsetails)
{ _Filices_ (Ferns)

(2) PHANEROGAMIA { A. _Gymnosperms_ (Firs, Yews, Cycads, &c.)
(Flowering { { _Monocotyledones_ (Grasses, Palms, Lilies,
Plants) { B. _Angiosperms_ { Orchids, &c.)
{ { _Dicotyledones_ (the great mass of Flowering
{ { Plants and Trees).

ST. GEORGE MIVART.

FOOTNOTES:

[4] CONTEMPORARY REVIEW, May, 1879, p. 261.

[5] _L. c._ p. 262.

[6] "A classification of any large portion of the field of Nature, in conformity to the foregoing principles, has hitherto been found practicable only in one great instance, that of animals."--_Logic_, third edition, 1851, vol. i., chap. viii. § 5, page 279.

[7] CONTEMPORARY REVIEW, July, 1879, pp. 716 and 717.

[8] _L. c._ p. 717.

[9] CONTEMPORARY REVIEW, July, 1879: "What are Living Beings?"

[10] Very small deer, commonly called in error musk-deer.

[11] The European beavers have abandoned the dam-building habit. They retained it, however, as late as the thirteenth century.

[12] By the Author in a Paper read before the Zoological Society in Nov. 1864. See also his "Man and Apes," Hardwicke, 1873; and the article "Ape" in the "Encyclopædia Britannica," vol. ii. p. 148.

[13] "Histoire Naturelle," tome xiv. p. 61, 1766.

[14] For an explanation of the zoological system of nomenclature which has been adopted since the time of Linnæus, see CONTEMPORARY REVIEW for May, page 262.

[15] See ante, p. 14.

[16] See CONTEMPORARY REVIEW for July, p. 710.

[17] See CONTEMPORARY REVIEW, July, p. 710.

[18] For a summary of our knowledge respecting this group, see the "Linnean Society's Journal," Vol. xiv. (Zoology), p. 136.

[19] A "spore" is a minute reproductive particle.

[20] See CONTEMPORARY REVIEW for July, 1879, p. 714.

[21] Some botanists think that yeast is no true and definite kind of plant, but that it is only a conglomeration of fungoid spores of divers sorts.

[22] This motion is that referred to at the bottom of page 696, in the CONTEMPORARY REVIEW for July, 1879, as _Cyclosis_.

[23] Some readers may be startled at the mode here adopted of primarily dividing the Phanerogams, and may object to it as opposed to usage; but reasons will be given later for the mode of division here adopted.

[24] The above-named plants may for our purpose be thus conveniently grouped together, according to the older fashion of botanists. Strictly speaking, however, they should be divided amongst several orders--_e.g._, hazel and hornbeam (_Corylaceæ_), the oak, beech, and chestnut (_Capuliferæ_), the birches (_Betulaceæ_), the willows (_Salicaceæ_), &c.

[25] Containing upwards of 2500 species.

THE ARTISTIC DUALISM OF THE RENAISSANCE.