590 THE STRUCTURE AND DEVELOPMENT 



THE MAMMALIAN OVARY (PI. 26). 



7'he literature of the mammalian ovary has been so often 

 dealt with that it may be passed over with only a few words. 

 The papers which especially call for notice are those of PflUger 1 , 

 Ed. van Beneden 2 , and especially Waldeyer 3 , as inaugurating the 

 newer view on the nature of the ovary, and development of the 

 ova ; and of Foulis 4 and Kolliker 5 , as representing the most 

 recent utterances on the subject. There are, of course, many 

 points in these papers which are touched on in the sequel, but 

 I may more especially here call attention to the fact that I have 

 been able to confirm van Beneden's statement as to the existence 

 of polynuclear protoplasmic masses. I have found them, how- 

 ever, by no means universal or primitive; and I cannot agree'in 

 a general way with van Beneden's account of their occurrence. 

 I have found no trace of a germogene (Keimfache) in the sense 

 of Pfliiger and Ed. van Beneden. My own results are most in 

 accordance with those of Waldeyer, with whom I agree in the 

 fundamental propositions that both ovum and follicular epithe- 

 lium are derived from the germinal epithelium, but I cannot 

 accept his views of the relation of the stroma to the germinal 

 epithelium. 



In the very interesting paper of Foulis, the conclusion is 

 arrived at, that while the ova are derived from the germinal 

 epithelium, the cells of the follicle originate from the ordinary 

 connective tissue cells of the stroma. Foulis regards the zona 

 pellucida as a product of the ovum and not of the follicle. To 

 both of these views I shall return, and hope to be able to shew 

 that Foulis has not traced back the formation of the follicle 

 through a sufficient number of the earlier stages. It thus comes 

 about that though I fully recognise the accuracy of his figures, 

 I am unable to admit his conclusions. Kolliker's statements 



1 Die Eierstocke d. Saugethiere it. d. Menschen, Leipzig, 1863. 



a "Composition et Signification de 1'cEuf," Acad. r. dc Be^i<jtie, 1868. 



3 Eierslock u. Ei. Leipzig, 1870. 



4 Trans, of Riyal Society, Edinburgh, Vol. XXVii. 1875, and Quarterly Journal 

 of Microscopical Science ) Vol. xvi. 



6 Verhandlung d. P/iys. AM. Gcsdhchaft, Wiirzl.urg, 1875, N. F. Bd. vin. 



