Blackman. — Spermatogenesis of Scolopendra. 



PLATE 6. — Continued. 



Fig. 94. Slightly later stage in the process of elongation. The posterior portion 

 of the cell shows a number of pseud opodia-like projections extend- 

 ing in various directions. 



Figs. 95, 96. Later stages in the elongation of the cell and the growth of the axial 

 filament. Archoplasmic bodies are seen at various points along the 

 course of the axial filament. Numerous deeply staining monilated 

 short filaments are seen in the cytoplasm. Some of the archoplasmic 

 spherules at the anterior end of the nucleus have been converted into 

 vesicles which are uniting (Fig. 95) to form larger ones. The chromatin 

 bodies are being broken up into flaky masses of granules. The " lateral 

 centrosomes " have entered the nucleus and are now indistinguishable 

 from the chromatin granules. 



Figs. 97, 98. Later stages. The acrosome vesicles are uniting to form a larger 

 vesicle. The nucleus is beginning to elongate in the direction of the 

 axial filament. All of the chromatin, except one dense body, the 

 karyosphere, is deposited in diffuse flaky masses upon the linin retic- 

 ulum. A small mass of archoplasm still remains around the proximal 

 end of the axial filament. 



Fig. 99. The archoplasmic vesicles have all united to form the acrosome, although 

 portions of the partition walls still remain. The chromatin is under- 

 going a chemical change, by which its staining reaction is altered. 

 The archoplasm at the base of the nucleus has become converted into 

 diffusely stained fibres arranged parallel to the axial filament. 



Fig. 100. The fusion of the acrosome vesicles is complete. In this cell the acro- 

 some has lost its fluid contents and become flattened. The chromatin 

 has undergone still further change. 



Fig. 101. A spermatid of the small type at about the stage of Figure 94, show- 

 ing the formation of false axial filaments at various places in the 

 cytoplasm. 



