Page:The Works of William Harvey (part 1 of 2).djvu/542

 organs of motion are distinguished, the spirits are perfected, and motion begins ; nor is it any longer nourished like a vege- table, by the roots, but, living the life of an animal, it is sup- ported by the mouth.

EXERCISE THE FIFTY-NINTH.

Of the uses of the entire egg.

Having now gone through the several changes and processes which must take place in the hen's egg, in order that it may produce a chick, Fabricius proceeds to consider the uses of the egg at large, and of its various parts; nor does he restrict him- self to the hen's egg, but condescends upon eggs in general. Among other things he inquires : wherefore some eggs are heterogeneous and composed of different elements ; and others are homogeneous and similar ? such as the eggs of insects, and those creatures that are engendered from the whole egg, viz. by metamorphosis, and are not engendered from one part of the egg, and nourished by another part.

I have no purpose myself of entering on a general consider- ation of eggs of all kinds and descriptions; I have not yet given the history of all, but only of the hen's egg ; so that I shall here limit myself to a survey of the uses of the common hen's egg, keeping in view the end of all its actions, which is nothing less than the production and completion of a new being, as Fabricius has well and truly said. 1

Among the points having reference to the whole egg, Fabri- cius speaks of the form, dimensions, and number of eggs. " The figure of the egg is round," he says, 2 " in order that the mass of the chick may be stowed in the smallest possible space ; for the same cause that God made the world round, namely, that it might embrace all things; and it is from this, as Galen con- ceives, that this figure is always felt to be most agreeable and consonant to nature. Further, as it has no angles exposed to injury from without, it is, therefore, the safest figure, and the

1 Loc. cit. p. 50. 2 Lib. x, de usu part.