6 j. bronte gatenby 



4. Spermatogenesis. 



(a) The Spermatogonium of S a c c o c i r r u s . 



The spermatogonium is a small rounded cell with a spherical 

 granular nucleus containing a karyosome. In PL 1, fig. 7, 

 is drawn one of a group or rosette of spermatogonia : there 

 was a spindle bridge as is common in such cases (sb). This 

 cell was drawn from a Mann-Kopsch preparation, and the 

 Golgi body (ga) shows as a number of black rods or batonettes 

 surrounding an archoplasm or centrosphere. In most sperma- 

 togonia the mitochondi'ia may be detected in the form of 

 a cloud lying in the region of the Golgi body, as in PI. 1 , fig. 7, 

 at M. 



(&) The Spermatocyte. 



Eosettes of spermatogonia grow synchronously to form 

 groups of spermatocytes, and during the growth stages the 

 mitochondria spread out through the cytoplasm, as in PI. 1, 

 fig. 1, M. The Golgi body grows too, and the numl)er of its 

 individual parts (Golgi rods, dictyosomes, or batonettes) also 

 increases, as shown at ga. The nucleus at this period is often 

 reniform. Possibly the most remarkable fact with regard to 

 the spermatogenesis of Saccocirrus is the presence in many, 

 if not all spermatocytes, of a group of true yolk-granules 

 (lipin) quite separate from either mitochondria or Golgi body : 

 in PI. 1, fig. 1, the yolk-granules are at y, and form a special 

 cell inclusion. By the Champy-Kull method the nucleus stains 

 bluish, the mitochondria and Golgi rods go dark red, the cyto- 

 plasm is yellowish, and the curious collection of yolk-granules 

 stain brownish green in the osmic acid of the Champy's fluid. 

 In PI. 1, fig. 1, at YC on the right, is drawn one of the yolk- 

 cells which accompanied this spermatocyte, and the yolk- 

 granules stained the same shade as the j^olk-spheres (y) in 

 the spermatocyte. 



In PI. 1, fig. 2, is a Kopsch preparation which shows the 

 efifect of prolonged osmication. The Golgi body (ga) has 

 reduced the OSO4 heavily, the mitochonchia do not show, 

 and the yolk-spherules are at y ; but besides all these there 



