In April or the first days of May, I discussed 

 with Burdach that I could no longer doubt the 

 origin of the ova from the ovary and that I very 

 much wanted to obtain a bitch mated a couple of 

 days earlier for the investigation .... 

 Burdach had such a bitch in his house and sacrificed 

 it. Opening it, I found some burst Graafian 

 follicles and others that were close to bursting. 

 On examining the ovary, I noticed in one follicle 

 a yellow spot, and then saw the same in many others, 

 but always only one spot. It was wonderful I I 

 thought, what could this be? I opened a follicle 

 and carefully carried the spot by a knife to a 

 watch glass filled with water, then put it under 

 the microscope. Looking into it, I jumped; how 

 surprising the discovery was, because evidently I 

 had seen a very small, distinctly formed, yellow 

 yolk ball. I had to take a breath before being 

 able to look again into the microscope, because 

 I was afraid that my vision may have deceived 

 me .... I saw in front of me a sharply outlined, 

 regular small ball within a thick membrane, which 

 was distinguished from the bird's yolk only by this 

 rough shape, somewhat falling behind the external 

 membrane. And thus the primary ovum of the dog was 

 found! It does not float in an undefined position 

 in the fairly viscous fluid of the Graafian vesicle, 

 but is attached to its wall and held to it by a wide 

 row of very large cells. 10 



With his report of this discovery, Baer wrote to the 

 members of the Petersburg Academy of Science to express his 

 happiness that he could publish his discovery under the 

 auspices of the Petersburg Academy. 



It is for whoever does not know how far Your Academy 

 exceeds all others in its services to the study of 

 the secrets of nature related to the formation of 

 new organic bodies. The investigators who established 



10. Baer, NACHRICHTEN, pp. 427-428 (311-312). 



290 



