OF REPRODUCTION. 95 



the general term, while the three others belong only to separate 

 phenomena, which may either exist unconjoined or altogether, ac- 

 cording to the class in which they happen to be observed. 



237. Thus polypi, which reproduce themselves by germs, have 

 generation, but no fecundation nor conception. The batracian rep- 

 tiles also produce germs; but these germs are of two species, those 

 of the male, and those of the female; they must be mixed in order 

 for reproduction to take place, but as the mixture is effected exte- 

 riorly, the batracians have no conception, although they have both 

 a generation and a fecundation. In birds there is retention of the 

 fecundated germ, and consequently, generation, fecundation, and 

 conception. In the mammiferae and man, the vivified and conceived 

 germ is developed within the animal; and there is, further, in these 

 cases, gestation, and even expulsion or parturition, at the end of 

 pregnancy. The function of reproduction then is composed, in the 

 human species, 1. Of generation, or the formation of the germ; 

 2. Oi fecundation, or the vivification of the germ; 3. 0( conception, 

 or the retention of the vivified germ; 4. Of gestation or pregnancy; 

 5. Of parturition or the expulsion of the ovum. 



SECTION 1. 



Of the Generation or Procreation of Germs. 



238. In the infusory animals which break to pieces of themselves, 

 and the zoophytes which we reduce to fragments that give birth to 

 an equal number of entire beings, germs are nothing more than 

 analogues of the general mass of the individuals from which they 

 have been separated. Their generation is, in this respect, analo- 

 gous to that of those plants that are multiplied by slips or grafts. 

 A little further on in the scale, germs cannot be produced except by 

 peculiar organs which constitute the sexes, and in that case the 

 sexes are sometimes united in the same individual, sometimes they 

 exist in two different individuals. Snails, oysters, a pretty consi- 

 derable number of other molusca, and all the monocecious plants 

 are in the first case, that is to say, they are hermaphrodites; the 

 dioecious plants, and almost all animals are found in the second; so 

 that reproduction is here bi-sexual, and the male and female germs 

 are always furnished by different individuals. 



§. I. Of the Female Crerm. 



239. In ascending the scale from fishes up to women, the female 

 germ appears to be formed in the ovary (233); it is always found 



