STUDIES ON GERM CELLS 



453 



years in doubt. Many investigators claim that they arise from 

 cells other than germ cells; these writers have been called by 

 Waldeyer ('06) 'duaUsts.' An equal ninnber of authorities be- 

 lieve that both Sertoli cells and spermatogonia originate fi^om 

 primordial germ cells; these are the 'monists.' 



g-ep- 



Fig. 24 Diagram to show the history of the germ cells in the embryo of the 

 guinea-pig. g.ep, germinal epithelium; (from Rubaschkin, '12). 



The researches of Montgomery and von Winiwarter have 

 decided the question, at least so far as man is concerned, in favor 

 of the monists. Montgomery's results are as follows: Of thirty 

 antepenultimate spermatogonia examined, twenty-three con- 

 tained each a rod-shaped structure (fig. 25, B, R) and it seems 

 probable that this peculiar body, which is identified by von 

 Winiwarter with the 'cristalloide de Lubarsch' (Lubarsch, '96), 

 is present in every cell of this generation. This rod is considered 



