The concoctive and metamorphic, the nutritive and augmentive faculties, which Fabricius would have it act through the qualities of hot, cold, moist and dry, without all consciousness, I maintain, on the contrary, work no less to a definite end, and with not less of artifice than the formative faculty, which Fabricius declares has knowledge and foresight of the future action and use of every particular part and organ. In the same way as the arts of the physician, cook and baker, in which heat and cold, moisture and dryness, and similar natural properties are employed, require the use of reason no less than the mechanical arts in which either the hands or various instruments are employed, as in the business of the blacksmith, statuary, potter, &c.; in the same way, as in the greater world, we are told that “All things are full of Jove,”—Jovis omnia plena—so in the slender body of the pullet, and in every one of its actions, does the finger of God or nature no less obviously appear.
Wherefore, if from manifestations it be legitimate to judge of faculties, we might say that the vegetative acts appear rather to be performed with art, election, and foresight, than the acts of the rational soul and mind; and this even in the most perfect man, whose highest excellence in science and art, if we may take the God for our guide, is that he KNOW HIMSELF.
A superior and more divine agent than man, therefore, appears to engender and preserve mankind, a higher power than the male bird to produce a young one from the egg. We acknowledge God, the supreme and omnipotent creator, to be present in the production of all animals, and to point, as it were, with a finger to his existence in his works, the parents being in every case but as instruments in his hands. In the generation of the pullet from the egg all things are indeed contrived and ordered with singular providence, divine wisdom, and most admirable and incomprehensible skill. And to none can these attributes be referred save to the Almighty, first cause of all things, by whatever name this has been designated,—the Divine Mind by Aristotle; the Soul of the Universe by Plato; the Natura Naturans by others; Saturn and Jove by the ancient Greeks and Romans; by ourselves, and as is seeming in these days, the Creator and Father of all that is in heaven and earth, on whom animals depend for their being, and at whose will and pleasure all things are and were engendered.
Moreover, as I have said, I neither hold this arrangement of the faculties of the vital principle, which Fabricius has placed at the head of his account of the organs of generation, as correct in itself, nor as useful or calculated to assist us in the matter we have in hand. For we do not attain to a knowledge of effects from a discussion of actions or faculties; the contrary is rather the case: from actions we ascend to a knowledge of faculties, inasmuch as manifestations are more cognizable to us than the powers whence they proceed, and the parts which we investigate already formed are more readily appreciated than the actions whence they proceed.
Neither is it well from the generation of a single chick from an egg, to venture upon general conclusions, which can in fact only be correctly arrived at after extensive observations on the mode of generation among animals at large. But of this matter I shall have more to say immediately.
Meantime, however, that we may come to the parts subservient to generation, as Fabricius says,[287] “let us consider and perpend in what order the organs subserving generation are produced—which are formed first, which last. In this investigation two bases are to be laid, one having reference to the corporeal, the other to the incorporeal; that is to say, to nature and the vital principle. The corporeal base,” he continues, “I call that which depends on and proceeds from the nature of the body, and of which illustrations are readily supplied from things made by art; as for example, that every building requires a foundation upon which it may be established and reared; from whence walls are raised, by which both floors and ceilings are supported; then are all the supplementary parts added and ornaments appended:—and so, in fact, does nature strive in the construction of the animal body; for first she forms the bones as a foundation, in order that all the parts of the body may grow upon and be appended to and established around them. These are the parts, in other words, that are first formed and solidified; for as the bones derive their origin from a very soft and membranous substance, and by and by become extremely hard, much time is required to complete the formation of a bone, and it is therefore that they are first produced. Hence Galen did not compare the formation of the animal body to every kind of artificial structure, but particularly to a ship; for he says, as the commencement and foundation of a ship is the keel, from which the ribs, circularly curved, proceed on either side at moderate distances from each other, like the sticks of a hurdle, in order that the whole fabric of the vessel may afterwards be reared upon the keel as a suitable basis; so in the formation of the animal body does nature, by means of the outstretched spine and the ribs drawn around it, secure a keel and suitable foundation for the entire superstructure, which she then raises and perfects.”
But experience teaches us that all this is very different in fact, and that the bones are rather among the last parts to be formed. The bones of the extremities and skull, and the teeth, do not arise any sooner than the brain, the muscles, and the other fleshy parts: in new-born fœtuses, perfect in other respects, the place of the bones is supplied by mere membranes or cartilages, which are only subsequently and in the lapse of time converted into bones; a circumstance which sufficiently appears in the crania of new-born infants, and in the state of their ribs and articulations.
And although it be true that the first rudiments of the body are seen in the guise of a recurved keel, still this is a soft mucous and jelly-like substance, which has no affinity in nature, structure, or office to bone; and although certain globules depend from thence, the destined rudiments of the head, still these contain no solid matter, but are mere vesicles full of limpid water, which are afterwards formed into the brain, cerebellum, and eyes, which are all subsequently surrounded by the skull, at a period, however, when the beak and nails have already acquired consistency and hardness.
This view of Fabricius is therefore both imperfect and incorrect; inasmuch as he does not think of what nature performs in fact in the work of generation, so much as of what in his opinion she ought to do, betrayed into this by his comparison with the edifice reared by art. As if nature had imitated art, and not rather art nature!—mindful of which he himself says afterwards:[288] “It were better to say that art learned of nature, and was an imitator of her doings; for, as Galen everywhere reminds us, nature is both older and displays greater wisdom in her works than art.”
And then when we admit that the bones are the foundation of the whole body, without which it could neither support itself nor perform any movement, it is still sufficient if they arise simultaneously with the parts that are attached to them. And indeed the things that are to be supported not yet existing, the supports would be established in vain. Nature, however, does nothing in vain; nor does she form parts before there is a use for them. But animals receive their organs as soon as the offices of these are required. The first basis of Fabricius, therefore, is distinctly overthrown by his own observations on the egg, and the comparison drawn by Galen.