Page:The Works of William Harvey (part 1 of 2).djvu/370

 EXERCISE THE TWENTY-FIFTH.

Certain Deductions from the preceding History of the Eyy.

Such is the history of the hen's egg; in which we have spoken of its production, and of its action or faculty to engender a chick, at too great length, it may appear to those who do not see the end and object of such painstaking, of such careful ob- servation. Wherefore I think it advisable here to state what fruits may follow our industry, and in the words of the learned Lord Verulam, to " enter upon our second vintage." Certain theorems, therefore, will have to be gathered from the history given ; some of which will be quite certain, some questionable and requiring further sifting, and some paradoxical and opposed to popular persuasion. Some of these, moreover, will have re- ference to the male, some to the female, several to the egg, and finally, a few to the formation of the chick. When these have been carefully discussed seriatim, we shall be in a condition to judge with greater certainty and facility of the generation of all other animals.

EXERCISE THE TWENTY-SIXTH.

Of the nature of the egg.

Of the theorems that refer to the egg, some teach us what it is, some show its mode of formation, and others tell of the parts which compose it.

It is certain, in the first place, that one egg produces one chick only. Although the egg be in a certain sense an external uterus, still it most rarely engenders several embryos, but by far the most frequently produces no more than a single pullet. And when an egg produces two chicks, which it does sometimes, still is this egg to be reputed not single but double, and as possessed of the nature and parts of two eggs.

For an egg is to be viewed as a conception proceeding from