194 M. E. Claparede on the Formation of the Egg 



several drops. These drops are perfectly identical with IMeiss- 

 nei-'s. They are not unfrequently met with larger than four or 

 five seminal corpuscles taken together. Here again, therefore, 

 the study of the unimpregnated females proves of great advan- 

 tage, and it is to be regretted that it was neglected by previous 

 observers. It is not improbable that the appearance of oil-drops 

 in the egg is to be regarded as a sign of its having missed its 

 object, and that it is destined to die and become retrograde. 

 We cannot assert that the few eggs in impregnated females in 

 which oil-drops are formed have escaped fecundation, for these 

 are also surrounded with the normal chorion, which is only 

 formed after fecundation has taken place. But w^e may easily 

 imagine that a fecundated egg may from some cause become 

 aborted, and die. It is therefore not impossible that the eggs 

 in question are to be regarded as abortive. 



We have received from a friend a confirmation of our ob- 

 servations : — Dr. de la Yalette obtained an unimpregnated female 

 of Ascaris mystax, and found the formation of oil-drops in great 

 quantity in its ova. By this, De la Yalette was induced, quite 

 independently of our investigations, to doubt Meissner's whole 

 theory of the conversion of the spermatozoa. 



It is not to be denied that the seminal corpuscles may enter 

 upon a fatty metamorphosis. We find here and there in the 

 genitalia of the females free corpuscles of a fatty aspect, which 

 are possibly produced by the metamorphosis of seminal cor- 

 puscles. But even then it is a question whether this meta- 

 morphosis is a necessary step in the cycle of development of the 

 seminal corpuscle, or whether the fatty metamorphosis is not a 

 consequence of its death. However it may be, we must declare 

 Meissner's observations to be insufficient, as he did not detect 

 the formation of oil-drops in unfecundated eggs; and the ques- 

 tion will not appear unsuitable, whether any of the oil-drops 

 observed by Meissner in the eggs of Ascarides were ever pro- 

 duced by tiie metamorphosis of seminal corpuscles. 



5. On the Movements of the Seminal Corpuscles. 



Hitherto Schneider^s observations upon the movements of the 

 seminal corpuscles in the Nematoidea* have neither been con- 

 firmed nor controverted. It is scarcely possible to doubt the 

 accuracy of the observations, as the report itself indicates great 

 care in the investigation. We may, how^ever, still ask whether 

 the corpuscles in question were true zoospermia, or perhaps 

 foreign beings, parasites; and, secondly, whether the move- 

 ments observed were normal. 



* Monatsber. der Berl. Akad., April 1856, 



