198 OVAEY AND PAROVARIUM, BY W. WALDEYER. 



The larger cells, which are the primordial eggs, occupy the axis of 

 the tube. The eggs originating in this manner, which recalls that 

 already given in regard to the Nematodes and Arthropods, are called 

 by Pfl tiger pre-ova or primary eggs (Ureier). These subsequently 

 increase in number by fission and germination, the products consti- 

 tuting the definitive eggs, that for a time remain connected with one 

 another in the interior of the tubes in the form of a chain by pro- 

 cesses of protoplasm, constituting the " egg chains " of Pfliiger. The 

 most important point in this now very generally accepted view, 

 namely, the multiplication of the primary ova, has not come under 

 my observation. The origin of the pre-ova and of the germinal 

 vesicles in a tube with csecal extremities, I must also, after what has 

 been stated above, consider to be doubtful. Moreover, Pfliiger, in 

 one of his own figures (plate iii., fig. 1), has represented a connection 

 existing between his tubes and the superficial columnar epithelium, 

 and has frequently remarked that the contents of the egg tubes mi 

 proceed from the ovarial epithelium, which he always considers to b< 

 a serous epithelium ; finally he returns again to the mode of orij 

 just referred to of the eggs in caecally ending tubes, and on this he 

 lays very great stress. Bischoff and others have stated that the de- 

 velopment of the ova terminates at the conclusion of foetal life, an 

 opinion with which my researches also lead me to coincide. Pfliiger, 

 on the other hand, has endeavoured to demonstrate the occurrence of 

 a post-embryonal and periodically recurring neoplastic formation of 

 ovarial tubes, and Kolliker is in accord with him on this point. The 

 latter believes (Gewebelehre, p. 560) we may admit the formation of 

 new follicles and ova to occur as a consequence of the growth of the 

 epithelium of pre-existent follicles. I do not mean to deny that even 

 in adults tubular and rounded groups of egg cells are present, the 

 separate inclusion of which in follicles is not completed, especially as 

 I have frequently seen similar formations in Dogs, Rabbits, and Birds, 

 as well as inflections of the superficial epithelium (see fig. 192) ; still 

 it remains an open question whether these are not the remains of 

 earlier periods of development ; at all events, I have not hitherto 

 been able to satisfy myself that they are not so. The statements 

 made by Koster (60) are to the same effect. 



In reviewing the results of our inquiry it would appear, then, 

 that the ova are not developed in and from the cellular elements 

 of the vascularized ovarial stroma, as most observers prior to 

 the suggestive work of Pfliiger sought to demonstrate, but 



