74 Translation from Purkinje 



usually find in addition a yellowish fluid in the abdominal cavity as 

 if mixed with a kind of albumen solution, and you will not infre- 

 quently find the same fluid poured out between the layers of the calyx. 

 I do not know what interpretation to place on it; it is perhaps to be 

 derived from an excessive effort of the blood to secrete yolk, like the 

 post-partum lactiferous abscesses in women. Never, to be sure, have 

 I found a mature ovum so ruptured that the yolk was diffused between 

 the layers of the calyx and the spherical form of the ovule distorted 

 into an irregular one. 



If, however, laying hens are under-nourished, the formation of eggs 

 ceases and those ovules which were approaching maturity undergo a 

 peculiar transformation; the inner membrane of the calyx is ruptured, 

 the yolk flows out into the spaces of the outer membrane, the ovule 

 decreases in size, the yolk becomes whitish and is resorbed; at that 

 time even the smaller ovules lose their spherical form and hang, flabby 

 and wrinkled, devoid of yolk. 



It is remarkable how quickly the muscle fibers vanish in the meso- 

 metrium of fowls which have stopped laying, so that even after a few 

 days you can discover only traces of them, milky in color and hardly 

 visible. But these matters require much detailed discussion. 



Concerning the disappearance of the 

 germinal vesicle. 



After the yolk has been received by the oviduct, it is invested during 



its progress with chalazae, the chalazal membrane, albumen, the 



[ 15 ] double shell membrane, and the shell. You will best understand the 



internal structure of these if you follow the changes the egg undergoes 



as it passes through the oviducal canal. 



If, in the first place, you investigate the cicatricula after the yolk 

 has been taken up by the infundibulum, you will nowhere find the 

 vesicle which has been described above in the cicatricula of the ovule. 

 Instead of the porus an internal circle of the blastoderm is now to be 

 seen, the cumvdus seems to have been changed into a white center, 

 and between the two a small circular area will be noted, besprinkled 

 with white gianvdes. If a mechanical explanation of this transforma- 

 tion be adequate, I would say that the yolk, in bursting from the 

 calyx and in being taken up by the infundibulum, is subjected to such 

 disturbance by the contractions of the latter that the exceedingly 

 delicate vesicle is ruptured. However, an account based on an opinion 

 ivill not fill up gaps in observation }^^ Repeated observations must be 

 made with the utmost acumen, unless perchance this naturally difficult 

 matter has withdrawn itself among mysteries not to be approached. 



