368 



THOMAS H. MONTGOMERY. 



The line of the Sertoli cell is therefore <h lennined In- the 

 presence of the rod; one Sertoli cell is produced to every three 



Antepenultimate 

 Spermatogonium 



Penultimate 

 Spermatogonia 



Ultimate 

 Spermatogonia 



Sertoli 

 cell 



ultimate Spermatogonia that lack the rod, or one Sertoli cell 

 to every twenty-five spermatids. 



2. THE ANTEPENULTIMATE SPERMATOGONIA (Fics. 1-8, PL. I.)- 

 These are the largest germ cells in the adult testis, and like 

 the other generations of Spermatogonia arc situated at the pe- 

 riphery of the seminiferous tubules. Frequently their nuclei are 

 of irregular shape, as shown in Fig. I. Within the nuclei ( Fig. 3) 

 are two kinds of nuclcolar structures: acidophilic plasmosomes 

 and basophilic bodies; it would take a detailed Mudy to deter- 

 mine whether the latter are chromatoid nuclei >H or modified 

 chromosomes (allosomes). In their cell bodie- ;nv tound ehro- 



