68 



CYTOLOGY 



CHAP. 



Chondriosomes in the spermatogenesis of Blatta germanica. (After Duesberg, A.Z., 1911.) The material 

 is prepared by Benda's method, and the chondriosomes are shown darker than the chromatin. A, 

 resting spermatogonium, filamentar chondriosomes distributed through the cytoplasm ; B, telophase of 

 a spermatogonial division ; chondriosomes mostly congregated in a bundle which is just cut across ; C, 

 young spermatocyte I. ; D, pachytene stage, chondriosomes temporarily conceutrated outside pole of nucleus ; 

 ]E, later prophase I. ; F, metaphase I. ; G, young spermatid ; chondriosomes massed into the very conspicuous 

 " Nebenkern " ; H, chondriosome mass divided into two ; I, the two cbondriosome masses growing out into 

 the tail of the spermatozoon, and clasping between them the axial filament ; J, the chondriosome mass now 

 forms a sheath round the axial filament, as shown in K, transverse section of the tail : L, ripe spermato- 

 zoon under a lower magnification. 



a.f, axial filament of tail ; ch, chondriosome mass ; n, nucleus. 



