ON THE SPERMATOGENESIS OF THE SILK-WORM. 139 



individual chromosomes are still to be recognized (fig. 75 a, 76). 

 An entire spermatozoon of this stage is represented in fig. 83. 

 Here the "Nebenkern" is no more to be seen as a distinct 

 body as before, but appears only as a thicker mass with a fine 

 thread-like prolongation. The mitosome has also completely 

 vanished from sight. 



Figs. 78, 79 and 80 show more advanced stages. The 

 chromosomes which are accumulated at the periphery of the 

 nucleus became now coagulated into a single compact mass and 

 form a deeply stainable body with a pointed end and a vacuole 

 in the centre of it. 



In fig. 82 is shown a spermatocyste with nearly matured 

 spermatozoa contained in it. In the head part of the cyste, is 

 seen a large cell metamorphosed from a nucleus of the cyste and 

 functioning as a supporting cell. The form of this cell is very 

 similar to the large supporting cell in the blind end of the 

 testicular follicle and may be compared with the cells des- 

 cribed and figured by Flemming in a spermatocyste of Sala- 

 mandra maculosa (9). 



ON THE " HODENZWISCHENKORPERCHEN." 



The " Hodenzwischenkorperchen " of van Beneden are also 

 to be found in the genital follicles of the silk-worm of both 

 sexes. In preparations fixed by Flemming's strong solution 

 and stained by Hermann's triple staining very conspicuous cells 

 are to be seen here and there (figs. 7 h, 84). They are round 

 with homogeneous protoplasm, in the centre or at the periphery 

 of which a deep stainable chromatin body, sometimes with va- 

 cuoles in it, is to be seen. Beside this, sometimes one or 

 more small deeply stainable spots occur in the cytoplasm. In 

 the early part of the formative stage, these cells are found 

 in the midst of the primary germ-cells, while in later stages 

 the entire mass of cells in a cyste presents such a structure 

 except those at the wall of the cyste (fig. 84). They are also 

 to be seen in the growing stage, where their structure is similar 

 to those of the formative stage. 



Sometimes the granular stainable spots in the cytoplasm 



(1) This is already described by Tichomiroff (37). 



