DIFFERENTSYSTEMS. 113 



* 



um, and, in place of augmenting, they become 

 ten times lefs than formerly, and they never 

 begin to grow till after their defcent from the 

 ovaria into the uterus. 



By comparing thefe obfervations of De Graaff 

 with thofe of Harvey, we will eafily perceive 

 that the latter has miifed the principal fads : 

 And, though there are feveral errors both in the 

 reafoning and iq the experiments of De GraaiF, 

 this anatomifi, as well as Malpighius, have dif- 

 covered themfelves to be better obfervers than 

 Harvey. They agree in all fundamental points, 

 and both of them contradidl Harvey, He per- 

 ceived not the alterations v.'hich take place in the 

 ovaria ; he faw not in the uterus thofe fmall 

 globules which contain the materials of genera- 

 tion, and which are called eggs by De Graaff, 

 He never fufpeded that the foetus exiftcd in the 

 egg ; and, though his experiments give us tole- 

 rably exact ideas concerning ^^ hat happens du- 

 ring the growth of the foetus, he furnifhes no 

 information concerning the commencement of 

 fecundation, nor concerning the firft expr.nfion 

 of the foetus. Schrader, a Dutch phyfician, 

 who had a great veneration for Harvey, acknow- 

 ledges that he cannot be truilcd in many articles, 

 and particularly in what relates to the firft for- 

 t mation of the embryo ; for the chick really ex- 

 ifts in the egg before incubation; and, he fays, 

 that Jofeph of Arcmatarius was the lirft who 

 Vol. II. H made 



