GENERATION OF ANIMALS, II. vii. 



approaches its completion the cotyledons become 

 smaller, and finally when it is completed they dis- 

 appear. Nature lays in a store of the blood-like 

 nourishment for the embryos in this part of the 

 uterus, as it were into breasts, and the body of 

 the cotyledon becomes as it were an eruption or 

 an inflammation owing to the fact that the numerous 

 cotyledons gradually get compacted together. While 

 the embryo is fairly small, and unable to take much 

 nourishment, they are large and plainly visible, but 

 when it has grown they shrink up. 



The great majority of the " stunted " " animals, 

 and of those that have front teeth in both jaws, have 

 no cotyledons in their uterus, but the umbilicus 

 extends to meet a single blood-vessel, which is a large 

 one and extends throughout the uterus. Some of 

 these animals produce one at a birth, others several ; 

 but what occurs when there is only one embryo 

 occurs also when- there are more. All this should be 

 studied ^\■ith the help of the illustrative diagrams 

 given in the Dissections and Researches. The embryos 

 are attached each to its umbihcus, and the umbilicus 

 is attached to the blood-vessel : they are arranged 

 one after the other along the stream of the blood- 

 vessel as it might be along a runnel in the garden ; 

 and there are membranes and a chorion around each 

 embryo. 



Those people ^ who say that children are nourished 

 in the uterus by means of sucking a bit of flesh are 



Littre). Tha view that the embryo sucked the " cotyledons " 

 was held by Diocles of Carystus (Wellmann, Fraginentsamm- 

 lung der sikellschen Arzte, Diocles fr. 37, 10 ff.) ; and accord- 

 ing to Jaeger (Diokles von Karystos, 166), Aristotle's detailed 

 treatment of the subject o'f cotyledons here is due to the fact 

 that Diocles was associated with him in the Lyceum. 



241 



