No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 'J J 



may be seen from the fact that some cell pockets contain almost 

 exclusively cells which are all in the same stage of development. 

 As these different pockets with cells are found adjoining each 

 other they give us a good guide by which we can correctly judge 

 as to the proper succession of the mitotic stages. These stages 

 will be enumerated below, beginning with the polymorphous 

 spermatogonia and ending with the spermatocytes. It will be 

 seen at once that the prophases last much longer than the 

 middle and end phases. 



In the polymorphous spermatogonia : the imperfect resting 

 stage. 



In the auxocytes : the imperfect resting stage, the bouquet 

 stage with twisted spireme, the perfect bouquet stage, the sepa- 

 rated segments. In other pockets we find all the succeeding 

 stages mixed together, though in a successive order in the same 

 pocket. 



In the spermatocytes : the pockets contain all the different 

 phases mixed together, though here also in a fairly regular suc- 

 cession from one end of the pocket to the other. 



In the spermatids we find pockets which contain cells in only 

 the checkerboard prophase. It thus appears that in certain 

 phases all the cells in the same pocket enter the same phase of 

 mitosis at the same time, and that these phases also last longer 

 than the others. It is interesting to note that in these longer 

 phases the cells remain mostly connected by spindle bridges, 

 and the supposition readily suggests itself that these spindle 

 bridges in some way actually regulate the starting time of the 

 prophases. 



VII. Structures of the Protoplasm. 

 Fibers, Granula, or Alveoles. 



As a perusal of the figures accompanying this paper shows, 

 the protoplasm has everywhere been figured as granular, except 

 in the confluent stages, where the dark staining prevents it from 

 being properly studied. 



As has been pointed out in the beginning of this paper, it is 

 useless to attempt to study the finer structures of the proto- 



