down by their weight. Serpents would also be hindered in their alternate zig-zag movements by a multitude of eggs in the abdomen. In the body of tortoises, with their hard and girding shell, there is no room for any store or increase of eggs ; nor would the abdomen of fishes suffice for the multitude of eggs they must spawn were these to grow to any size. It was, therefore, matter of necessity that those creatures should lay their eggs imperfect. It seems most natural that an animal should retain and cherish its conception in its interior until the foetus it produces has come to maturity; but nature sees her- self compelled, as it were, occasionally to permit the premature birth of various eggs, and to provide them, without the body of the parent, with the nourishment they require for their com- plete development. As to everything that refers to the evolu- tion of the foetus, all animals are engendered from an oviform primordium ; I say oviform, not as meaning that it has the pre- cise configuration of an egg, but the nature and constitution of one ; this being common in generation, that the vegetal pri- mordium whence the foetus is produced, including the nature of an egg, corresponding in its proportions to the seed of a plant, pre-exists. In all vegetal primordia, consequently, whether eggs, or having the form of eggs, there are inherent the nature and conditions of an egg, properties which the seeds of plants have in common with the eggs of animals. The primordium of any animal, whatsoever, is therefore called seed and fruit; and in like manner the seed of every plant is spoken of as a kind of conception or egg.
And this is the reason why Aristotle says : J " Animals that engender internally have something formed in the fashion of an egg after their first conception : there is a fluid contained within a delicate membrane, like en egg without the shell. And this is the cause why the disorders of the conception, which are apt to occur in the early period, are called discharges." Such a discharge is particularly observed among women when they miscarry in the course of the first or second month. I have repeatedly seen such ova aborted at this time ; and such was the one which Hippocrates has described as having been thrown off by the female pipe-player in consequence of a fall.
De Gen. Anim. lib. iii, cap. 9.
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