Page:The Works of William Harvey (part 1 of 2).djvu/625

 notice, at the same time we are sure to see some rare and foreign birds, as if the latter had chased the former from some remote corner of the earth. Now in both of these classes of creatures the time for bringing forth their young is the same. Physicians, too, when these phenomena occur, are enabled to predict the approach of sundry strange diseases. Bees bring forth in the month of May, when honey abounds; wasps in the summer, when the fruit is ripe; and this is analogous to what takes place in viviparous animals, who produce their young at the period when their milk is best adapted for their offspring. But other animals of the non-migratory classes, in the same way, at stated seasons seek a place to deposit their young as they do a store of food. And thus it results that the countryman is able to decide what are the proper seasons for ploughing, sowing, and getting in his harvest, forming his opinion chiefly from the approach of flocks of birds, and especially of the seminivora. There are, however, some animals in whom there is no fixed time for production, and this is chiefly the case with those which are called domestic, and live with the human species. These both copulate and produce their young at uncertain seasons, and the reason probably is to be sought for in the larger quantity of food they consume, and the consequent inordinate salacity. But in these, as in the human species, the process of parturition is often difficult and dangerous.

There are other animals also on whom the course of the moon has influence, and which consequently copulate and bring forth their young at certain periods of the year—rabbits, mice, and the human female may be instanced. "For the moon," observes Plutarch, "when half full, is represented as greatly efficacious in shortening the pains of labour, and this she effects by moderating and relaxing the humours—hence, I think, those surnames of Diana are derived, Locheia, i.e. the tutelar deity of childbirth, and Eilytheia, otherwise Lucina; for Diana and the moon are synonymous."

"In all other animals," says Pliny, "there are stated seasons and periods for production and utero-gestation; in man alone are they undetermined." And this is, to a great extent, true;