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 foetuses, 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, cere- bellum, 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 in- correct; inasmuch as he does not think of what nature per- forms in fact in the work of generation, so much as of what in his opinion she ought to do, betrayed into this by his compa- rison with the edifice reared by art. As if nature had imitated art, and not rather art nature ! mindful of which he himself says afterwards : l "It were better to say that art learned of nature, and was an imitator of her doings ; for, as Galen every- where 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 dis- tinctly overthrown by his own observations on the egg, and the comparison drawn by Galen.
1 Op. cit. p. 44.
