He appears to have come nearer the truth where he says:[289] “The other basis of the parts to be formed first or last is obtained from nature, that is, from the vital principle by which the animal body is ruled and directed. If there be two grades of this principle, the vegetative and animal, the vegetative must be held prior in point of nature and time, inasmuch as it is common to plants and animals; and assuredly the organs officiating in the vegetative office will be engendered and formed before those that belong to the sensitive and motive principle, especially to the chief organs which are in immediate relationship with the governing principle. Now these organs are two in especial—the liver and the heart: the liver as seat of concupiscence, of the vegetative or nutritive faculty; the heart, as the organ whose heat maintains and perfects the vegetative and every other faculty, and in this way has most intimate connexions and relations with the vegetative force. Whence, if after the third day you see the heart palpitating in the point where the chick is engendered, as Aristotle bears witness to the fact that you can, you will not be surprised but rather be disposed to admit that the heart belongs to the vegetative degree and exists for its sake. It is also consonant with reason that the liver should be engendered simultaneously with the heart, but should lie perdue or hidden, as it does not pulsate. And Aristotle himself admits that the heart and liver exist in the animal body for similar reasons; so that where there is a heart there also is a liver discovered. If the heart and liver be the parts first produced, then, it is also fair to suppose that the other organs subserving these two should be engendered in the same manner,—the lungs which exist for the sake of the heart; and, for the sake of the liver, almost all the viscera which present themselves in the abdomen.”
Still is all this very different from the sequence we witness in the egg. Nor is it true that the liver is engendered simultaneously with the heart; nor does the salve avail with which he would cover that infirmity where he says that the liver is concealed because it does not palpitate; for the eyes and vena cava and carina are all conspicuous enough from the commencement, although none of them palpitate. How come the liver and lungs, if they be then extant, to be visible without any palpitation? And then Fabricius himself has indicated a minute point situated in the centre of his figure of the chick of the fourth day, without stating, however, that it had any pulsation; and this he did not perceive to be the heart, but rather believed it to be the rudiment of the body. It is certain, therefore, that Fabricius spoke only from conjecture and preconceived opinion of the origin of the liver; even in the same way as others have done, Aldrovandus and Parisanus among the number, who, lighting upon two points, and perceiving that they did not pulsate simultaneously, straightway held that one was the heart, the other the liver. As if the liver ever pulsated, and these two points were aught but the two pulsating vesicles replying to each other by alternate contractions, in the way and manner we have indicated in our history!
Fabricius, therefore, is either deceived or deceives, when he says, “In the first stage of the production of the chick, the liver, heart, veins, arteries, lungs, and all the organs contained in the cavity of the abdomen, are engendered together; and in like manner are the carina, in other words, the head with the eyes and entire vertebral column and thorax engendered.” For the heart, veins, and arteries are perfectly distinguished some time before the carina; the carina, again, is seen before the eyes; the eyes, beak, and sides before the organs contained in the cavity of the abdomen; the stomach and intestines before the liver or lungs; and there are still other particulars connected with the order of production of the parts in generation, of which we shall speak by and by.
He is also mistaken when he would have the vegetative portion of the vital principle prior in nature and time to the sensitive and motive element. For that which is prior in nature is mostly posterior in the order of generation. In point of time, indeed, the vegetative principle is prior; because without it the sensitive principle cannot exist: an act—if the act of an organic body—cannot take place without organs; and the sensitive and motive organs are the work of the vegetative principle; the sensitive soul before the existence of action, is like a triangle within a quadrangle. But nature intended that that which was primary and most noble should also be primary; wherefore the vegetative force is by nature posterior in point of order, as subordinate and ministrative to the sensitive and motive faculties.
EXERCISE THE FIFTY-FIFTH.
Of the order of the parts according to Aristotle.
The following appear to be Aristotle’s views of the order of generation:[290] “When conception takes place, the germ comports itself like a seed sown in the ground. For seeds likewise contain a first principle, which, existing in the beginning in potentia, by and by when it manifests itself, sends forth a stem and a root, by which aliment is taken up; for increase is indispensable. And so in a conception, in which all the parts of the body inhere in potentia, and the first principle exists in a state of special activity.”
This principle in the egg—the body analogous to the seed of a vegetable—we have called with Fabricius the spot or cicatricula, and have spoken of it as a very primary part of the egg, as that in which all the other parts inhere in potentia, and from whence each in its order afterwards arises. In this spot, in fact, is contained that—whatever it may be—by which the egg is made productive; and here is the first action of the formative faculty, the first effect of the vegetative heat revealed.
This spot, as we have said, dilates from the very commencement of the incubation, and expands in circles, in the centre of which a minute white speck is displayed, like the shining point in the pupil of the eye; and here anon is discovered the punctum saliens rubrum, with the ramifications of the sanguiferous vessels, and this as soon as the fluid, which we have called the colliquament, has been produced.
“Wherefore,” adds Aristotle,[291] “the heart is the first part perceived in fact; and this is in conformity not only with sense, but also with reason. For as that which is engendered is already disjunct and severed from both parents, and ought to rule and regulate itself like a son who comes of age and has his separate establishment, it must therefore possess a principle, an intrinsic principle, by which the order of the members may be subsequently determined, and whatever is necessary to the constitution of a perfect animal arranged. For if this principle were at any time extrinsic, and entered into the body at a subsequent period, you would not only be in doubt as to the time at which it entered, but as every part is distinct, you would also see it as necessary that that should first exist from which the other parts derive both increase and motion.” The same writer elsewhere[292] asserts: “This principle is a portion of the whole, and not anything added, or included apart. For,” he proceeds, “the generation of the animal completed, does this principle perish, or does it continue? But nothing can be shown existing intrinsically which is not a part of the whole organized being, whether it be plant or animal; wherefore it would be absurd to maintain that the principle in question perished after the formation either of any one or of any number of parts; for what should form those that were not yet produced? Wherefore,” he continues further, “they say not well who with Democritus assert that the external parts of animals are those first seen, and then the internal parts, as if they were rearing an animal of wood and stone, for such a thing would include no principle within itself. But all animals have and hold a principle in their interior. Wherefore the heart is seen as the first distinct part in animals that have blood; for it is the origin of all the parts, whether similar or dissimilar; and the creature that begins to feel the necessity of nourishment, must already be possessed by the principle of an animal and a full-grown fœtus.”