376 THOMAS H. MONTGOMERY. 



the similarity in color of the cells of Sertoli and the- interstitial 

 cells after staining with cyanine, chromotrop and erythrosine. 

 Though Bardeleben thus holds the two kinds of cells to be of 

 different origin, he nevertheless thinks that the Sertoli cells give 

 rise to "a rudimentary second form of spermatozomes." Benda 

 ('94, '98), and Waldeyer relying upon him, considers the cell 

 of Sertoli to arise from the indifferent cylindrical peritoneal cells. 

 The dualists generally hold that a differentiated Sertoli cell re- 

 mains functionally active during the life of the individual and 

 does not regenerate more than the distal portion of its cell body; 

 and they are also of the opinion that the cells of Sertoli proliferate 

 themselves by division amitotically, according to Bardeleben 

 and Stephan, or mitotically according to Benda. On the other 

 hand Prenant ('87), Schoenfeld ('01), Regaud ('99) and Bugnion 

 ('06) consider both cells of Sertoli and spermatogonia to be de- 

 rived from one kind of cells, by a process of division of labor; 

 and this is in agreement with the results of most writers who 

 have studied the origin of the follicular cells of the ovaries and 

 testes of invertebrates the follicular or nurse cell being generally 

 regarded as a modified germ cell. Yet Regaud and Stephan 

 ('02) hold that the fully formed Sertoli cells proliferate germ 

 cells as well as nourish them; while Bugnion believes "the 

 primordial spermatogonium gives place to a plurinucleate plate 

 (part of the parietal synctium) which contains in a common cyto- 

 plasm spermatic nuclei and sertolian nuclei," after which the 

 germ cells delimit themselves from the syncytium that remains 

 as a Sertoli cell. 



My conclusions differ practically in their entirety from those 

 of the writers mentioned. In tin- human testis the cells of Sertoli 

 are of common origin with the germ cells, one out of every four 

 ultimate spermatogonia becoming a Sertoli cell. Sertoli cells arc 

 thus not differentiated from the germ cells merely in early fatal 

 history, but so long as ultimate spermatogonia continue to be 

 produced. A Sertoli cell of man once differentiated does not, 

 so far as I have observed, divide again, and consequently does 

 not give rise to germ cells; further, a Sertoli cell die- completely 

 after the spermatozoa that are associated with it depart Irom 

 its surface, and it does not persist to nourish a second ^em-ration of 

 spermatozoa. There being one Sertoli cell to every three detini- 



