Page:The Works of William Harvey (part 1 of 2).djvu/319

 all this amid the din of dogs, and men, and horns, and sur- rounded by an unknown and gloomy wood. We should not, therefore, be greatly surprised when we see those who have experience telling by what hen each particular egg in a number has been laid. I wish there were some equally ready way from the child of knowing the true father.

The principal difference between eggs, however, is their fecundity or barrenness the distinction of fruitful eggs from hypenemic, adventitious, or wind eggs. Those eggs are called hypenemic, (as if the progeny of the wind,) that are produced without the concourse of the male, and are unfit for setting ; although Varro 1 declares that the mares, in Lusitania, conceive by the wind. For zephyrus was held a fertilizing wind, whence its name, as if it were frujj^epo'e, or life bringing. So that Virgil says :

And Zephyrus, with wanning breath resolves The bosom of the ground, and melting rains Are poured o'er all, and every field brings forth.

Hence the ancients, when with this wind blowing in the spring season, they saw their hens begin laying, without the concur- rence of the cock, conceived that zephyrus, or the west wind, was the author of their fecundity. There are also what are called addle, and dog-day eggs, produced by interrupted incu- bation, and so called because eggs often rot in the dog-days, being deserted by the hens in consequence of the excessive heat ; and also because at this season of the year thunder is frequent ; and Aristotle 2 asserts that eggs die if it thunders whilst the hen is sitting.

Those eggs are regarded as prolific, which, no unfavorable circumstances intervening, under the influence of a gentle heat, produce chicks. And this they will do, not merely through the incubation of the mother, but of any other bird, if it be but of sufficient size to cherish and cover them, or by a gentle tem- perature obtained in any way whatever. " Eggs are hatched with the same celerity," says Aristotle, 3 " spontaneously in the ground, as by incubation. Wherefore in Egypt, it is the custom

1 De Re Rust. lib. ii, cap. 1.

2 Hist. Anim. lib. vi, cap. 2 ; Plin. Hist. Nat. lib. x, cap. 54. 3 Ibid.