142 



but that which was in the very centre of the cicatricu- 

 la, or tread. And perhaps the nidus necessary for 

 their formation is so proportioned to their bulk, that 

 it can hardly contain more than one animalcula. 

 This is certainly the case in oviparous kinds. And all 

 the difference between the viviparous and the oviparous 

 is, that in the former, the egg is nothing but the cica- 

 tricula with its yolk: so that the foetus must draw its 

 nourishment from the womb. Whereas, in the ovi- 

 parous, the egg itself is a kind of womb, contain- 

 ing all that is needful for the animal, till it is hatched, 



2. It is acknowledged, that the foetus in the womb, 

 is not connected with it, for a considerable time after 

 conception : that it is wholly loose from it, and is only 

 a little round egg, with the embryo in the midst, 

 -which sends forth its umbilical vessels by degrees, and 

 at last lays hold on the womb. Hence it is plain,that 

 the cicatricula, which nourishes the animalcula, does 

 not spring from the womb, but only falls into it, as 

 a fit soil, whence it may draw nourishment for the 

 foetus. 



Yet there is a difficulty which presses equally on 

 those, who suppose the animal to spring either from the 

 male or female parent. It is the case of monsters. In a 

 mule, for instance: the body is of the form of the mare : 

 whereas the feet, the tail, and the ears, resemble thoie 

 of its sire. If the male supplied the arlimalcula, one 

 would imagine the foetus should always be of the same 

 species with the male. If the female, it should be of 

 her kind : whereas monsters are of both : as if the 

 main part of the animal lay in the egg, and the im- 

 pregnation only conveyod or changed the extremities. 



Yet, that some animals iirst exist, not in the seed of 

 the male, but wholly in the egg of the female, unde. 

 niably appears from the case of frogs and toads. (And 

 why may it not be the same thing with other animals ?) 

 The eggs of these are not impregnated by the male, 

 till they issue from the womb. It is while they are 

 ejected,, that he fecundates them with his seminal 1U 



