Chapter XXVIII: Introduction (3)

The folds which appear oblique and transverse in the interior of the uterus are fleshy substances; they have a fine white or milky colour, and a sluggish fluid oozes from them, so that the whole of the interior of the uterus, as well the body as the process, is moistened with an abundance of thin albumen, whereby the vitellus as it descends is increased, and the albumen that is deposited around it is gradually perfected.

The uterus of the fowl is rarely found otherwise than containing an egg, either sticking in the spiral process or arrived in the body of the organ. If you inflate this process when it is empty it then presents itself as an oblique and contorted tube, and rises like a turbinated shell or cone into a point. The general arrangement of the spirals and folds composing the uterus, is such as we have already observed it in the vulva: there is a ready enough passage for the descending egg, but scarce any return even for air blown in towards the superior parts.

The processus uteri with its spirals, very small in the young pullet, is so much diminished in the hen which has ceased laying, that it shrinks into the most delicate description of membrane, and then entirely disappears, so that no trace of it remains, any more than of the ovary or infundibulum: nothing but a certain glandular-looking and spongy mass appears in the place these bodies occupied, which in a boiled fowl tastes sweet, and bears some affinity to the pancreas and thymus of young mammiferous animals, which, in the vernacular tongue, are called the sweetbread.

The uterus and the processus uteri are connected with the back by means of a membranous attachment, which Fabricius designates by the name of “mesometrium; because the second uterus, together with this vascular and membranous body, may very fairly be compared with the intestines and the mesentery.” For, as the intestine is bound down by the mesentery, so is this portion of the uterus attached to the spinal column by an oblong membranous process; lest by being too loose, and getting twisted, the passage of the yelks should be interfered with, instead of having a free and open transit afforded them as at present. The mesometrium also transmits numerous blood-vessels surcharged with blood, to each of the folds of the uterus. In its origin, substance, structure, use, and office, this part is therefore analogous to the mesentery. Moreover, from the fundus of the uterus lengthwise, and extending even to the infundibulum, there is a ligament bearing some resemblance to a tape-worm, similar to that which we notice in the upper part of the colon. It is as if a certain portion or stripe of the external tunic had been condensed and shortened in such a manner that the rest of the process is thrown into folds and cells: were you to draw a thread through a piece of intestine taken out of the body, and to tie this thread firmly on one side, you would cause the other side of the bowel to pucker up into wrinkles and cells; [even so is it with the uterus of the fowl.]

This then, in brief, is the structure of the uterus in the fowl that is laying eggs: fleshy, large, extensible both longitudinally and transversely, tortuous or winding in spirals and convolutions from the cloaca upwards, in the line of the vertebral column, and continued into the infundibulum.

EXERCISE THE NINTH.

_Of the extrusion of the egg, or parturition of the fowl, in general._

The yelk, although only a minute speck in the ovary, gaining by degrees in depth of colour and increasing in size, gradually acquires the dimensions and characters that distinguish it at last. Cast loose from the cluster, it descends by the infundibulum, and, transmitted through the spirals and cells of the processus uteri, it becomes surrounded with albumen; and this, without in any place adhering to the uterus (as was rightly observed by Fabricius in opposition to Aristotle), or growing by means of any system of umbilical vessels; but as the eggs of fishes and frogs, when extruded and laid in the water provide and surround themselves with albumen, or as beans, vetches, and other seeds and grains swell when moistened, and thence supply nourishment to the germs that spring from them, so, from the folds of the uterus that have been described, as from an udder, or uterine placenta, an albuminous fluid exudes, which the vitellus, in virtue of its inherent vegetative heat and faculty, attracts and digests into the surrounding white. There is, indeed, an abundance of fluid having the taste of albumen, contained in the cavity of the uterus and entangled between the folds that cover its interior. In this way does the yelk, descending by degrees, become surrounded with albumen, until at last, having in the extreme part of the uterus acquired a covering of firmer membranes and a harder shell, it is perfected and rendered fit for extrusion.

EXERCISE THE TENTH.

_Of the increase and nutrition of the egg._

Let us hear Fabricius on these topics. He says: “As the action of the stomach is to prepare the chyle, and that of the testes to secrete the seminal fluid, (because in the stomach chyle is discovered, and in the testes semen,) so we declare the act of the uterus in birds to be the production of eggs, because eggs are found there. But this, as it appears, is not the only action of uteri; to it must be added the increase of the egg, which succeeds immediately upon its production, and which proceeds until it is perfected and attains its due size. For a fowl does not naturally lay an egg until it is perfect and has attained to its proper dimensions. The office of the uterus is, therefore, the growth as well as the generation of the egg; but growth implies and includes the idea of nutrition; and, as all generation is the act of two principles, one the agent, another the matter, the agent in the production of eggs is nothing else than the organs or instruments indicated, viz., the compound uterus; and the matter nothing but the blood.”

We, studious of brevity, and shunning all controversy, as in duty bound, as we readily admit that the office and use of the uterus is the procreation of the egg, so do we maintain the “adequate efficient,” as it has been called, the immediate agent to inhere in the egg itself; and we assert farther, that the egg is both engendered and made to increase, not by the uterus, but by a certain natural principle peculiar to itself; and that this principle flows from the whole fowl into the rudiments of the vitellus, and whilst it was yet but a speck, and under the influence either of the calidum innatum or of nature, causes it to be nourished and to grow; just as there is a certain faculty in every particle of the body which secures its nutrition and growth.

As regards the manner in which the yelk is surrounded by the albumen, Aristotle appears to have believed[145] that in the sharp end of the egg (where he placed the commencement of the egg), whilst it was yet surrounded by soft membranes, there existed an umbilical canal, by which it was nourished; a view which Fabricius[146] challenges, denying that there is any such canal, or that the vitellus has any kind of connexion with the uterus. He farther lessens the doubt in regard to the albumen of the extruded egg, observing, that “the egg increases in a two-fold manner, inasmuch as the uterus consists of two portions, one superior, another inferior; and the egg itself consists of two matters--the yelk and the white. The yelk increases with a true growth, to wit, by means of the blood, which is sent to it through the veins whilst it is yet connected with the vitellarium. The albumen, however, increases and grows otherwise than the yelk; viz., not by means of the veins, nor by proper nutrition like the yelk, but, by juxtaposition, adhering to the vitellus as it is passing through the second uterus.”

But my opinion is, that the egg increases everywhere in the same manner as the yelk does in the cluster; viz. by an inherent concocting principle; with this single difference, that in the ovary the nourishment is brought to it by means of vessels, whilst in the uterus it finds that which it imbibes already prepared for it. Juxtaposition of parts is equally necessary in every kind of nutrition and growth, and so also are concoction and distribution of the applied nutriment. Nor is one of these to be less accounted true nutrition than the other, inasmuch as in both there is accession of new aliment, apposition, agglutination, and transmutation of particles. Nor can vetches or beans, when they attract moisture from the earth through their skins, imbibing it like sponges, be said with less propriety to be nourished than if they had obtained the needful moisture through the mouths of veins; and trees, when they absorb the dew and the rain through their bark, are as truly nourished as when they pump them in by their roots. With reference to the mode in which nutrition is effected, we have set down much in another place. It is another difficulty that occupies us at this time, viz., whether the yelk, whilst it is acquiring the white, does not make a certain separation and distinction in it; whether, in the course of the increase, a more earthy portion does not subside into the yelk or middle of the egg as towards the centre, which Aristotle believed, and another lighter portion surrounds this. For between the yelk which is still in the cluster, and the yelk which is found in the middle of a perfect egg, there is this principal difference, that although the former be of a yellow colour, still, in point of consistence, it rather resembles the white; and by boiling, it is, like the latter, thickened, compacted, inspissated, and becomes divisible into layers; whilst the yelk of the perfect egg is rendered friable by boiling, and is rather of an earthy consistency, not thick and gelatinous like albumen.

EXERCISE THE ELEVENTH.

_Of the covering or shell of the egg._

It will now be proper, having spoken of the production of eggs, to treat of their parts and diversities. “An egg,” says Fabricius, “consists of a yelk, the albumen, two chalazæ, three membranes, viz. one proper to the vitellus, two common to the entire egg, and a shell. To these two others are to be added, which, however, cannot be correctly reckoned among the parts of an egg; one of these is a small cavity in the blunt end of the egg, under the shell; the other is a very small white spot, a kind of round cicatricula connected with the surface of the yelk. The history of each of these parts and accidents must now be given more particularly, and we shall begin from without and proceed inwards.

“The external covering of the egg, called by Pliny the cortex and putamen, by Quintus Serenus the testa ovi, is a hard but thin, friable and porous covering, of different colours in different cases--white, light green, speckled, &c. All eggs are not furnished with a shell on their extrusion: the eggs of serpents have none; and some fowls occasionally, though rarely, lay eggs that are without shells. The shell, though everywhere hard, is not of uniform hardness; it is hardest towards the upper end.” From this Fabricius[147] opines that we are to doubt as to the matter of which, and the season at which the shells of eggs are produced. Aristotle[148] and Pliny[149] affirm that the shell is not formed within the body of the fowl, but when the egg is laid; and that as it issues it sets by coming in contact with the air, the internal heat driving off moisture. And this, says Aristotle,[150] is so arranged to spare the animal pain, and to render the process of parturition more easy. An egg softened in vinegar is said to be easily pushed into a vessel with a narrow mouth.

Fabricius was long indisposed to this opinion, “because he had found an egg within the body of the fowl covered with a hard shell; and housewives are in the daily practice of trying the bellies of their hens with their fingers in order that they may know by the hardness whether the creatures are likely to lay that day or not.” But by-and-by, when “he had been assured by women worthy of confidence, that the shells of eggs became hardened in their passage into the air, which dissipates a certain moisture diffused over the egg on its exit, fixing it in the shell not yet completely hardened;” and having afterwards “confirmed this by his own experience,” he altered his opinion, and came to the conclusion, “that the egg surrounded with a shell, and having a consistency betwixt hard and soft, hardened notably at the moment of its extrusion, in consequence, according to Aristotle’s views, of the concretion and dissipation of the thinner part of a certain viscid and tenacious humour, bedewed with which the egg is extruded; sticking to the recent shell this humour is dried up and hardened, the cold of the ambient air contributing somewhat to the effect. Of all this,” he says, “you will readily be satisfied if you have a fowl in the house, and dexterously catch the egg in your hand as it is dropping.”

I was myself long fettered by this statement of Aristotle, indeed until certain experience had assured me of its erroneousness; for I found the egg still contained in the uterus, almost always covered with a hard shell; and I once saw an egg taken from the body of a living fowl, and still warm, without a shell but covered with a tenacious moisture; this egg, however, did not acquire any hardness through the concretion or evaporation of the moisture in question, as Fabricius would have us believe, neither was it in any way changed by the cold of the surrounding air; but it retained the same degree of softness which it had had in the uterus.

I have also seen an egg just laid by a fowl, surrounded by a complete shell, and this shell covered externally with a soft and membranous skin, which however did not become hard. I have farther seen another hen’s egg covered with a shell everywhere except at the extremity of the sharp end, where a certain small and soft projection remained, very likely such as was taken by Aristotle for the remains of an umbilicus.

Fabricius, therefore, appears to me to have wandered from the truth; nor was I ever so dexterous as to catch an egg in its exit, and discover it in the state between soft and hard. And this I confidently assert, that the shell is formed internally, or in the uterus, and not otherwise than all the other parts of the egg, viz. by the peculiar plastic power. A statement which I make all the more confidently because I have seen a very small egg covered with a shell, contained within another larger egg, perfect in all respects, and completely surrounded with a shell. An egg of this kind Fabricius calls an ovum centeninum; and our housewives ascribe it to the cock. This egg I showed to his serene Majesty King Charles, my most gracious master, in the presence of many persons. And the same year, in cutting up a large lemon, I found another perfect but very small lemon included within it, having a yellow rind like the other; and I hear that the same thing has frequently been seen in Italy.

It is a common mistake with those who pursue philosophical studies in these times, to seek for the cause of diversity of parts in diversity of the matter whence they arise. Thus medical men assert that the several parts of the body are both engendered and nourished by diverse matters, either the blood or the seminal fluid; viz. the softer parts, such as the flesh, by the thinner matter, the harder and more earthy parts, such as the bones, &c. by the firmer and thicker matter. But we have elsewhere refuted this too prevalent error. Nor do they err less who, with Democritus, compose all things of atoms; or with Empedocles, of elements. As if _generation_ were nothing more than a separation, or aggregation, or disposition of things. It is not indeed to be denied, that when one thing is to be produced from another, all these are necessary, but generation itself is different from them all. I find Aristotle to be of this opinion; and it is my intention, by-and-by, to teach that out of the same albumen (which all allow to be uniform, not composed of diverse parts,) all the parts of the chick, bones, nails, feathers, flesh, &c. are produced and nourished. Moreover, they who philosophize in this way, assign a material cause [for generation], and deduce the causes of natural things either from the elements concurring spontaneously or accidentally, or from atoms variously arranged; they do not attain to that which is first in the operations of nature and in the generation and nutrition of animals; viz. they do not recognize that efficient cause and divinity of nature which works at all times with consummate art, and providence, and wisdom, and ever for a certain purpose, and to some good end; they derogate from the honour of the Divine Architect, who has not contrived the shell for the defence of the egg with less of skill and of foresight than he has composed all the other parts of the egg of the same matter, and produced it under the influence of the same formative faculty.

Although what has already been said be the fact, namely, that the egg, even whilst contained in the uterus, is provided with a hard shell, still the authority of Aristotle has always such weight with me that I never think of differing from him inconsiderately; and I therefore believe, and my observations bear me out in so much, that the shell does gain somewhat in solidity from the ambient air upon its extrusion; that the sluggish and slippery fluid with which it is moistened when laid, immediately becomes hardened on its exposure to the air. For the shell, whilst the egg is in the uterus, is much thinner and more transparent, and smoother on the surface; when laid, however, the shell is thicker, less translucid, and the surface is rough--it appears as if it were powdered over with a fine white dust which had but just adhered to it.

Let us, as we are upon this subject, expatiate a little:--

In the desert islands of the east coast of Scotland, such flights of almost every kind of sea-fowl congregate, that were I to state what I have heard from parties very worthy of credit, I fear I should be held guilty of telling greater stories than they who have committed themselves in regard to the Scottish geese produced, as they say, from the fruits of certain trees that had fallen into the sea. These geese the narrators themselves had never seen so produced; but I will here relate that which I have myself witnessed.

There is a small island which the Scots call the Bass Island (and speaking of this one will suffice for all), situated in the open ocean, not far from the shore, of the most abrupt and precipitous character, so that it rather resembles one huge rock or stone than an island, and indeed it is not more than a mile in circumference. The surface of this island in the months of May and June is almost completely covered with nests, eggs, and young birds, so that you can scarce find free footing anywhere; and then such is the density of the flight of the old birds above, that like a cloud they darken the sun and the sky; and such the screaming and din that you can scarce hear the voice of one who addresses you. If you turn your eyes below, and from your lofty stance and precipice regard the sea, there you perceive on all sides around an infinite variety of different kinds of sea-fowl swimming about in pursuit of their prey: the face of the ocean is very like that of a pool in the spring season, when it appears swarming with frogs; or to those sunny hills and cliffy mountains looked at from below, that are covered with numerous flocks of sheep and goats. If you sail round the island and look up, you see on every ledge and shelf, and recess, innumerable flocks of birds of almost every size and order; more numerous than the stars that appear in the unclouded moonless sky; and if you regard the flights that incessantly come and go you may imagine that it is a mighty swarm of bees you have before you. I should scarcely be credited did I name the revenue which was annually derived from the feathers, the eggs, and the old nests, which, as useful for firing, are all made objects of traffic by the proprietor; the sum he mentioned to me exceeds credibility. There was this particular feature which, as it refers to our subject, I shall mention, and also as it bears me out in my report of the multitudes of sea-fowl: the whole island appears of a brilliant white colour to those who approach it,--all the cliffs look as if they consisted of the whitest chalk; the true colour of the rock, however, is dusky and black. It is a friable white crust that is spread over all, which gives the island its whiteness and splendour, a crust, having the same consistency, colour, and nature as an egg-shell, which plasters everything with a hard, though friable and testaceous kind of covering. The lower part of the rock, laved by the ebbing and flowing tide, preserves its native colour, and clearly shows that the whiteness of the superior parts is due to the liquid excrements of the birds, which are voided along with the alvine fæces; which liquid excrements, white, hard, and brittle like the shell of the egg, cover the rock, and, under the influence of the cold of the air, incrust it. Now this is precisely the way in which Aristotle and Pliny will have it that the shell of the egg is formed. None of the birds are permanent occupants of the island, but visitors for purposes of procreation only, staying there for a few weeks, in lodgings, as it were, and until their young ones can take wing along with them. The white crust is so hard and solid, and adheres so intimately to the rock, that it might readily be mistaken for the natural soil of the place.

The liquid, white, and shining excrement is conveyed from the kidneys of birds by the ureters, into the common receptacle or cloaca; where it covers over the alvine fæces, and with them is discharged. It constitutes, in fact, the thicker portion of the urine of these creatures, and corresponds with that which, in our urine, we call the hypostase or sediment. We have already said something above on this topic, and have entered into it still more fully elsewhere. We always find an abundance of this white excrement in mews; where hawks besmear walls beside their perches, they cover them with a kind of gypseous crust, or make them look as if they were painted with white lead.

In the cloaca of a dead ostrich I found as much of this gypseous cement as would have filled the hand. And in like manner the same substance abounds in tortoises and other oviparous animals; discharged from the body it soon concretes either into a friable crust, or into a powder which greatly resembles pulverized egg-shells, in consequence of the evaporation of its thinner part.

Among the many different kinds of birds which seek the Bass island for the sake of laying and incubating their eggs, and which have such variety of nests, one bird was pointed out to me which lays but one egg, and this it places upon the point of a rock, with nothing like a nest or bed beneath it, yet so firmly that the mother can go and return without injury to it; but if any one move it from its place, by no art can it be fixed or balanced again; left at liberty, it straightway rolls off and falls into the sea. The place, as I have said, is crusted over with a white cement, and the egg, when laid, is bedewed with a thick and viscid moisture, which setting speedily, the egg is soldered as it were, or agglutinated to the subjacent rock.

An instance of like rapid concretion may be seen any day at a statuary’s, when he uses his cement of burnt alabaster or gypsum tempered with water; by means of which the likeness of one dead, or the cast of anything else may be speedily taken, and used as a mould.

There is also in like manner a certain earthy or solid something in almost all liquids, as, for example, tartar in wine, mud or sand in water, salt in lixivium, which, when the greater portion of the water has been dissipated, concretes and subsides; and so do I conceive the white sediment of birds to descend along with the urine from the kidneys into the cloaca, and there to cover over and incrust the egg, much as the pavement of a mews is plastered over by falcons, and every cliff of the aforementioned island by the birds that frequent it; much also as chamber utensils, and places where many persons make water, become covered with a yellow incrustation; that substance, in fact, concreting externally, of which calculi in the kidneys, bladder, and other parts are formed. I did formerly believe then, as I have said, persuaded especially by the authority of Aristotle and Pliny, that the shell of the hen’s egg was formed of this white sediment, which abounds in all the oviparous animals whose eggs are laid with a hard shell, the matter concreting through contact with the air when the egg was laid. And so many additional observations have since strengthened this conclusion, that I can scarcely keep from believing that some part at least of the shell is thus produced.

Nevertheless, I would say with Fabricius: “Let all reasoning be silent when experience gainsays its conclusions.” The too familiar vice of the present age is to obtrude as manifest truths, mere fancies, born of conjecture and superficial reasoning, altogether unsupported by the testimony of sense.

For I have very certainly discovered that the egg still contained in the uterus, in these countries at least, is covered with its shell; although Aristotle and Pliny assert the contrary, and Fabricius thinks that “it is not to be too obstinately gainsaid.” In warmer places, perhaps, and where the fowls are stronger, the eggs may be extruded soft, and for the most part without shells. With us this very rarely happens. When I was at Venice in former years, Aromatarius, a learned physician, showed me a small leaf which had grown between the two valves of a peascod, whilst with us there is nothing more apparent in these pods than a small point where the germ is about to be produced. So much do a milder climate, a brighter sky, and a softer air, conduce to increase and rapidity of growth.

EXERCISE THE TWELFTH.

_Of the remaining parts of the egg._

We have already spoken partially of the place where, the time when, and the manner how the remaining parts of the egg are engendered, and we shall have something more to add when we come to speak of their several uses.

“The albumen,” says Fabricius,[151] “is the _ovi albus liquor_ of Pliny, the _ovi candidum_ of Celsus, the _ovi albor_ of Palladius, the _ovi album et albumentum_ of Apicius, the λευκὸν of the Greeks, the ώοῡ λεύκωμα of Aristotle, the ὄρνιθος γάλα, or bird’s milk of Anaxagoras. This is the cold, sluggish, white fluid of the egg, of different thickness at different places (thinner at the blunt and sharp ends, thicker in other situations,) and also in variable quantity (for it is more abundant at the blunt end, less so at the sharp end, and still less so in the other parts of the egg), covering and surrounding the yelk on every side.”

In the hen’s egg, however, I have observed that there are not only differences in the albumen, but two albumens, each surrounded with its proper membrane. One of these is thinner, more liquid, and almost of the same consistence as that humour which, remaining among the folds of the uterus, we have called the matter and nourishment of the albumen; the other is thicker, more viscid, and rather whiter in its colour, and in old and stale eggs, and those that have been sat upon for some days, it is of a yellowish cast. As this second albumen everywhere surrounds the yelk, so is it, in like manner, itself surrounded by the more external fluid. That these two albumens are distinct appears from this, that if after having removed the shell you pierce the two outermost membranes, you will perceive the external albuminous liquid to make its escape, and the membranes to become collapsed and to sink down in the dish; the internal and thicker albumen, however, all the while retains its place and globular figure, inasmuch as it is bounded by its proper membrane, although this is of such tenuity that it entirely escapes detection by the eye; but if you then prick it, the second albumen will forthwith begin to flow out, and the mass will lose its globular shape; just as the water contained in a bladder escapes when it is punctured; in like manner the proper investing membrane of the vitellus being punctured, the yellow fluid of which it consists escapes, and the original globular form is destroyed.

“The vitellus,” says Fabricius,[152] “is so called from the word vita, because the chick lives upon it; from its colour it is also spoken of as the yellow of the egg, having been called by the Greeks generally, χρυσὸν, by Hippocrates χλωρὸν, and by Aristotle ώχρὸν and λεκυθὸν; the ancients, such as Suidas in Menander, called it νεοττὸν, i. e. the chick, because they believed the chick to be engendered from this part. It is the smoothest portion of the egg, and is contained within a most delicate membrane, immediately escaping if this be torn, and losing all figure; it is sustained in the middle of the egg; and in one egg is of a yellow colour, in another of a tint between white and yellow; it is quite round, of variable size, according to the size of the bird that lays the egg, and, according to Aristotle, of a deeper yellow in water birds, of a paler hue in land birds.” The same author[153] also maintains that “the yellow and the white of an egg are of opposite natures, not only in colour but in qualities; for the yellow is inspissated by cold, which the white is not, but is rather rendered more liquid; and the white, on the contrary, is thickened by heat, which the yellow is not, unless it be burned or over-done, and it is more hardened and dried by boiling than by roasting.” As in the macrocosm the earth is placed in the centre, and is surrounded by the water and the air, so is the yelk, the more earthy part of the egg, surrounded by two albuminous layers, one thicker, another thinner. And, indeed, Aristotle[154] says that, “if we put a number of yelks and whites together, and mix them in a pan, and then boil them with a slow and gentle fire, that the whole of the yelks will set into a globular mass in the middle, and appear surrounded by the whites.” But many physicians have been of opinion that the white was the colder portion of the egg. Of these matters, however, more by and by.

The chalazæ, the treads or treadles (gralladura Ital.) are two in number in each egg, one in the blunt, another in the sharp end. The larger portion of them is contained in the white; but they are most intimately connected with the yelk, and with its membrane. They are two long-shaped bodies, firmer than the albumen and whiter; knotty, not without a certain transparency like hail, whence their name; each chalaza, in fact, is made up of several hailstones, as it seems, connected by means of albumen. One of them is larger than the other, and this extends from the yelk towards the blunt end of the egg; the other and smaller chalaza stretches from the yelk towards the sharp end of the egg. The larger is made up of two or three knots or seeming hailstones, at a trifling distance from one another, and of successively smaller size.

The chalazæ are found in the eggs of all birds, and in wind and unprolific as well as in perfect or prolific eggs, duly disposed in both their extremities. Whence the supposition among housewives that the chalazæ are the tread or spermatic fluid of the cock, and that the chick is generated from them is discovered to be a vulgar error. But Fabricius himself, although he denies that they consist of the semen of the cock, still gives various reasons for maintaining that “they are the immediate matter which the cock fecundates, and from which the chick is produced;” a notion which he seeks to prop by this feeble statement: “because in a boiled egg, the chalazæ are so contracted on themselves that they present the figure of a chick already formed and hatched.” But it is not likely that several rudiments of a single fœtus should be wanted in one egg, neither has any one ever discovered the rudiments of the future chick save in the blunt end of the egg. Moreover the chalazæ present no sensible difference in eggs that are fecundated by the intercourse of the two sexes, from those of eggs that are barren. Our distinguished author is therefore mistaken in regard to the use of the chalazæ in the egg, as shall farther be made to appear by and by.

In the eggs of even the smallest birds there is a slender filament, the rudiments of the chalazæ, to be discovered; and in those of the ostrich and cassowary I have found, in either end of the egg very thick chalazæ, of great length, and very white colour, made up of several globules gradually diminishing in size.

A small cavity is observed in the inside of an egg under the shell, at the blunt end; sometimes exactly in the middle, at other times more to one side, almost exactly corresponding to the chalaza that lies below it. The figure of this cavity is generally circular, though in the goose and duck it is not exactly so. It is seen as a dark spot if you hold an egg opposite a candle in a dark place, and apply your hand edgeways over the blunt end. In the egg just laid it is of small size,--about the size of the pupil of the human eye; but it grows larger daily as the egg is older, and the air is warmer; it is much increased after the first day of incubation; as if by the exhalation of some of the more external and liquid albumen the remainder contracted, and left a larger cavity; for the cavity in question is produced between the shell and the membrane which surrounds the whole of the fluids of the egg. It is met with in all eggs; I have discovered it, even in those that are still contained in the uterus, as soon as they had become invested with the shell. They who are curious in such matters say that if this cavity be in the point or end of the egg it will produce a male, if towards the side, a female. This much is certain: if the cavity be small it indicates that the egg is fresh-laid; if large, that it is stale. But we shall have occasion anon to say more on this head.

There is a white and very small circle apparent in the investing membrane of the vitellus, which looks like an inbranded cicatrice, which Fabricius therefore calls cicatricula; but he makes little of this spot, and looks on it rather as an accident or blemish than as any essential part of the egg. The cicatricula in question is extremely small; not larger than a tiny lentil, or the pupil of a small bird’s eye; white, flat, and circular. This part is also found in every egg, and even from its commencement in the vitellarium. Fabricius, therefore, is mistaken when he thinks that this spot is nothing more than the trace or cicatrice of the severed peduncle, by which the egg was in the first instance connected with the ovary. For the peduncle, as he himself admits, is hollow, and as it approaches the vitellus expands, so as to surround or embrace, and inclose the yelk in a kind of pouch: it is not connected with the yelk in the same way as the stalks of apples and other fruits are infixed, and so as to leave any cicatrice when the yelk is cast loose. And if you sometimes find two cicatriculæ in a large yelk, as Fabricius states, this might, perhaps, lead to the production of a monster and double fœtus, (as shall be afterwards shown), but would be no indication of the preexistence of a double peduncle. He is, however, immensely mistaken when he imagines that the cicatricula serves no purpose; for it is, in fact, the most important part of the whole egg, and that for whose sake all the others exist; it is that, in a word, from which the chick takes its rise. Parisanus, too, is in error, when he contends that this is the semen of the cock.

EXERCISE THE THIRTEENTH.

_Of the diversities of eggs._

“The word ovum, or egg, is taken in a twofold sense, proper and improper. An ovum, properly so designated, I call that body to which the definition given by Aristotle[155] applies: An egg, says he, is that from part of which an animal is engendered, and the remainder of which is food for the animal so produced. But I hold that body to be improperly styled an egg which is defined by Aristotle[156] in the same place, to be that from the whole of which an animal is engendered; such as the eggs of ants, flies, spiders, some butterflies, and others of the tribe of extremely small eggs; which Aristotle almost always fears to commit himself by calling eggs, but which he rather styles vermiculi.” What precedes is from Fabricius;[157] but we, whose purpose it is to treat especially of the generation of the hen’s egg, have no intention to speak of the differences of all kinds of eggs; we shall limit ourselves to the diversities among hen’s eggs.

The more recently laid are whiter than the staler, because by age, and especially by incubation, they become darker; the cavity in the blunt end of a stale egg is also larger than in a recent egg; eggs just laid are also somewhat rough to the feel from a quantity of white powder which covers the shell, but which is soon rubbed off, when the egg becomes smoother as well as darker. New-laid eggs, unbroken, if placed near a fire will sweat, and are much more palatable than those that have been kept for some time--they are, indeed, accounted a delicacy by some. [Fruitful] eggs, after two or three days’ incubation, are still better flavoured than stale eggs; revived by the gentle warmth of the hen, they seem to return to the quality and entireness of the egg just laid. Farther, I have boiled an egg to hardness, after the fourteenth day of incubation, when the chick had already begun to get its feathers, when it occupied the middle of the egg, and nearly the whole of the yelk remained, in order that I might better distinguish the position of the chick: I found it lying, as it were, within a mould of the albumen, and the yelk possessed the same agreeable flavour and sweetness as that of the new-laid egg, boiled to the same degree of hardness. The yelk taken from the ovarium of a live fowl, and eaten immediately, tastes much sweeter raw than boiled.

Eggs also differ from one another in shape; some are longer and more pointed, others rounder and blunter. According to Aristotle,[158] the long-shaped and pointed eggs produce females; the blunt, on the contrary, yield males. Pliny,[159] however, maintains the opposite. “The rounder eggs,” he says, “produce females, the others males;” and with him Columella[160] agrees: “He who desires to have the greater number of his brood cocks, let him select the longest and sharpest eggs for incubation; and on the contrary, when he would have the greater number females, let him choose the roundest eggs.” The ground of Aristotle’s opinion was this: because the rounder eggs are the hotter, and it is the property of heat to concentrate and determine, and that heat can do most which is most powerful. From the stronger and more perfect principle, therefore, proceeds the stronger and more perfect animal. Such is the male compared with the female, especially in the case of the common fowl. On the contrary, again, the smaller eggs are reckoned among the imperfect ones, and the smallest of all are regarded as entirely unproductive. It was on this account too that Aristotle, to secure the highest quality of eggs, recommends that the hens be frequently trodden. Barren and adventitious eggs, he asserts, are smaller and less savoury, because they are humid and imperfect. The differences indicated are to be understood as referring to the eggs of the same fowl; for when a certain hen goes on laying eggs of a certain character, they will all produce either males or females. If you understand this point otherwise, the guess as to males or females, from the indications given, would be extremely uncertain. Because different hens lay eggs that differ much in respect of size and figure: some habitually lay more oblong, others, rounder eggs, that do not differ greatly one from another; and although I sometimes found diversities in the eggs of the same fowl, these were still so trifling in amount that they would have escaped any other than the practised eye. For as all the eggs of the same fowl acquire nearly the same figure, in the same womb or mould in which the shell is deposited, (much as the excrements are moulded into scybala in the cells of the colon,) it necessarily falls out that they greatly resemble one another; so that I myself, without much experience, could readily tell which hen in a small flock had laid a given egg, and they who have given much attention to the point, of course succeed much better. But that which we note every day among huntsmen is far more remarkable; for the more careful keepers who have large herds of stags or fallow deer under their charge, will very certainly tell to which herd the horns which they find in the woods or thickets belonged. A stupid and uneducated shepherd, having the charge of a numerous flock of sheep, has been known to become so familiar with the physiognomy of each, that if any one had strayed from the flock, though he could not count them, he could still say which one it was, give the particulars as to where it had been bought, or whence it had come. The master of this man, for the sake of trying him, once selected a particular lamb from among forty others in the same pen, and desired him to carry it to the ewe which was its dam, which he did forthwith. We have known huntsmen who, having only once seen a particular stag, or his horns, or even his print in the mud, (as a lion is known by his claws,) have afterwards been able to distinguish him by the same marks from every other; some, too, from the foot-prints of deer, seen for the first time, will draw inferences as to the size, and grease, and power of the stag which has left them; saying whether he were full of strength, or weary from having been hunted; and farther, whether the prints are those of a buck or a doe. I shall say thus much more: there are some who, in hunting, when there are some forty hounds upon the trace of the game, and all are giving tongue together, will nevertheless, and from a distance, tell which dog is at the head of the pack, which at the tail, which chases on the hot scent, which is running off at fault; whether the game is still running, or is at bay; whether the stag have run far, or have but just been raised from his lair. And all this amid the din of dogs, and men, and horns, and surrounded by an unknown and gloomy wood. We should not, therefore, be greatly surprised when we see those who have experience telling by what hen each particular egg in a number has been laid. I wish there were some equally ready way from the child of knowing the true father.

The principal difference between eggs, however, is their fecundity or barrenness--the distinction of fruitful eggs from hypenemic, adventitious, or wind eggs. Those eggs are called hypenemic, (as if the progeny of the wind,) that are produced without the concourse of the male, and are unfit for setting; although Varro[161] declares that the mares, in Lusitania, conceive by the wind. For zephyrus was held a fertilizing wind, whence its name, as if it were ζωηφερὀς, or life bringing. So that Virgil says:

And Zephyrus, with warming breath resolves
The bosom of the ground, and melting rains
Are poured o’er all, and every field brings forth.

Hence the ancients, when with this wind blowing in the spring season, they saw their hens begin laying, without the concurrence of the cock, conceived that zephyrus, or the west wind, was the author of their fecundity. There are also what are called addle, and dog-day eggs, produced by interrupted incubation, and so called because eggs often rot in the dog-days, being deserted by the hens in consequence of the excessive heat; and also because at this season of the year thunder is frequent; and Aristotle[162] asserts that eggs die if it thunders whilst the hen is sitting.

Those eggs are regarded as prolific, which, no unfavorable circumstances intervening, under the influence of a gentle heat, produce chicks. And this they will do, not merely through the incubation of the mother, but of any other bird, if it be but of sufficient size to cherish and cover them, or by a gentle temperature obtained in any way whatever. “Eggs are hatched with the same celerity,” says Aristotle,[163] “spontaneously in the ground, as by incubation. Wherefore in Egypt, it is the custom to bury them in dung, covered with earth. And there was a tale in Syracuse, of a drunken fellow, who was accustomed to continue his potations until a number of eggs, placed under a mat bestrewed with earth, were hatched.” The empress Livia, is also said to have carried an egg in her bosom until a chick was produced from it. And in Egypt, and other countries, at the present time, chickens are reared from eggs placed in ovens. “The egg, therefore,” as Fabricius[164] truly says, “is not only the uterus, and place where the generation of the chick proceeds, but it is that upon which its whole formation depends; and this the egg accomplishes as agent, as matter, as instrument, as place, and as all else that concurs.”

For it is certain that the chick is formed by a principle inherent in the egg, and that nothing accrues to a perfect egg from incubation, beyond the warmth and protection; in the same way as to the chick when disclosed, the hen gives nothing more than her warmth and her care, by which she defends it from the cold and from injury, and directs it to its proper food. The grand desideratum, therefore, once the chickens are hatched, is that the hen lead them about, seek for and supply them with proper food, and cherish them under her wings. And this you will not easily supply by any kind of artifice.

Capons, and hybrids between the common fowl and the pheasant, produced in our aviaries, will incubate and hatch a set of eggs; but they never know how to take care of the brood--to lead them about properly, and to provide with adequate care for their nurture.

And here I would pause for a moment, (for I mean to treat of the matter more fully by and by,) to express my admiration of the perseverance and patience with which the females of almost every species of bird, sit upon the nest for so many days and nights incessantly, macerating their bodies, and almost destroying themselves from want of food; what dangers they will face in defence of their eggs, and when compelled to quit them for ever so short a time, through necessity, with what eagerness and haste they return to them again, and brood over them! Ducks and geese, when they quit the nest for a few minutes, cover and conceal it with straw. With what true magnanimity do these ill-furnished mothers defend their eggs! which, after all, perhaps, are mere wind or addle eggs, or not their own, or artificial eggs of chalk or ivory;--it is still the same, they defend all with equal courage. It is truly a remarkable love which birds display for inert and lifeless eggs; and their solicitude is repaid by no kind of advantage or enjoyment. Who does not wonder at the affection, or passion rather, of the clucking hen, which can only be extinguished by a drenching with cold water. In this state of her feeling she neglects everything,--her wings droop, her feathers are unpruned and ruffled, she wanders about restless and dissatisfied, disturbing other hens on their nests, seeking eggs everywhere, which she commences forthwith to incubate; nor will she be at peace until her desire has been gratified, until she has a brood to lead about with her, upon which she may expend her fervour, which she may cherish, feed, and defend. How pleasantly are we moved to laughter when we see the poor hen following to the water the supposititious brood of ducklings she has hatched, wandering restlessly round the pool, attempting to wade after them to her own imminent peril, and by her noises and various artifices striving to entice them back to the shore!

According to Aristotle,[165] barren eggs do not produce chicks because their fluids do not thicken under incubation, nor is the yelk or the white altered from its original constitution. But we shall revert to this subject in our general survey of generation.

Our housewives, that they may distinguish the eggs that are addled from those that will produce chicks, take them from the fourteenth to the sixteenth day of the incubation, and drop them softly into tepid water, when the spoilt ones sink, whilst the fruitful ones swim. If the included chick be well forward, and moves about with alacrity, the egg not only rolls over but even dances in the water. And if you apply the egg to your ear for several days before the hatching, you may hear the chick within kicking, scratching, and even chirping. When the hen that is sitting hears these noises, she turns the eggs and lays them otherwise than they were, until the chicks, getting into a comfortable position, become quiet; even as watchful mothers are wont to treat their infants when they are restless and cry in their cradles.

Hens lay eggs in variable numbers: “Some hens,” says the philosopher,[166] “except the two winter months, lay through the whole year; some of the better breeds will lay as many as sixty eggs before they show a disposition to sit; though these eggs are not so prolific as those of the commoner kinds. The Adrianic hens are small, and lay every day, but they are ill-tempered, and often kill their young ones; they are particoloured in their plumage. Some domestic fowls will even lay twice a day; and some, by reason of their great fecundity, die young.”

In England some of the hens lay every day; but the more prolific commonly lay two days continuously and then miss a day: the first day the egg is laid in the morning, next day in the afternoon, and the third day there is a pause. Some hens have a habit of breaking their eggs and deserting their nests; whether this be from disease or vice is not known.