more limpid part ; and the rest of the colliquament in which the fo3tus swims is like crude milk, or milk deprived of its purer portion. The purer part does not require any of that ulterior concoction of which the remainder stands in need; and to un- dergo which it is taken into the stomach, where it is trans- muted into chyle. Similar to this is the crude and watery milk which is found in the breasts immediately after parturition. The liquefied albumen of the egg, and the crude or watery milk of the mammae seem to have in all respects the same colour, taste, and consistence. For the first flow of milk is serous and watery, and women are wont to express water from their breasts before the milk comes white, concocted, and perfect.
Just as the colliquament found in the crop of the chick is a kind of crude milk, whilst the same fluid discoveredin the stomach is concocted, white, and curdled; so in viviparous animals, before the milk is concocted in the mammae, a kind of dew and colli- quament makes its appearance there, and the colliquament only puts on the semblance of milk after it has undergone concoc- tion in the stomach. And so it happens, in Aristotle's opinion, that the first and most essential parts are formed out of the purer and thinner portion of the colliquament, and are increased by the remaining more indifferent portion after it has under- gone elaboration by a new digestion in the stomach. In the same way are the other less important parts developed and maintained. Thus has nature, like a fond and indulgent mother, been sedulous rather to provide superfluity, than to suffer any scarcity of things necessary. Or it might be said to be in conformity with reason to suppose that the foetus, now grown more perfect, should also be nourished in a more per- fect manner, by the mouth, to wit, and by a more perfect kind of aliment, rendered purer by having undergone the two ante- cedent digestions and been thereby freed from the two kinds of excrementitious matter. In the beginning and early stages, nourished by the ramifications of the umbilical veins, it leads in some sort the life of a plant ; the body is then crude, white, and imperfect; like plants, too, it is motionless and impas- sive. As soon, however, as it begins by the mouth to par- take of the same aliment farther elaborated, as if feeling a diviner influence, boasting a higher grade of vegetative exist- ence, the gelatinous mass of the body is changed into flesh, the
