No. I.] SPERMATOGENESIS OF BATRACHOSEPS. m 



granospheres are being reconstituted at the poles of the central spindle. In the 

 upper cell are seen three fragments of plasmosphere near the cell wall. The pole 

 of the upper central spindle rests on the cytoplasmic membrane, while the pole of 

 the other cell ends in the cytoplasm. A linin network is forming between the 

 chromosomes in the lower nucleus. Archosomes and accessory archosomes are 

 too much washed out to be distinctly visible. The mid-body consists of a double 

 row of granules. 



Fig. 69. Spermatocyte in the chrysanthemum stage. The linin network is 

 appearing among the chromosomes. The fiber cones are pushing out the cell 

 walls in both cells. The accessory archosomes at the poles of the cones are well 

 defined ; some are also seen on the cone fibers. The fragments of the plasmo- 

 sphere are seen in both cells, stained dark red. There are two archosomes at the 

 pole of the central spindle of the lower cell. At a deeper level the false nuclear 

 membrane was distinctly seen in each cell. 



Fig. 70. Spermatocytes emerging from the chrysanthemum stage and entering 

 the second prophase. The two cells are only connected by a spindle bridge. 

 The chromosomes are separated, though some are yet connected by chromoplasts, 

 which latter are now located at the angle where the two prongs of the chromo- 

 some meet. The cytoplasmic membrane is yet seen around the nucleus, the latter 

 having filled out the vacuole. But a true nuclear membrane or karyotheca has 

 also been formed directly around the chromosomes, showing that the two mem- 

 branes are of different origin. Accessory archosomes are seen on the cytoplasmic 

 or false nuclear membrane; some are also seen on the cone fibers. Two fragments 

 of plasmosphere in the lower cell along the new cell wall. The granosphere is 

 being reconstituted, especially around the pole of the central spindle in the upper 

 cell. The chromosomes in the lower cell are further advanced than those in the 

 upper cell. 



Fig. 71. Spermatocyte in the checkerboard stage, the chromomeres being 

 much separated. The fiber cones are yet pushing out the cell wall, though some 

 of them have evidently begun to dissolve. The new nuclear membrane has 

 formed around each nucleus. A large plasmosphere in each cell. Accessory 

 archosomes at the pole of each fiber cone. A mid-body on the spindle bridge. 



Fig. 72. Spermatocytes connected by a spindle bridge on which is seen a mid- 

 body. The fiber cones are disappearing. The two spheres are reconstituting 

 separately, later on to be united. Many accessory archosomes on the fibers as 

 well as in the cytoplasm. 



Fig. 73. Spermatocytes in the checkerboard stage, though further advanced 

 than the last figured cell. The fiber cones, however, are less degenerated, and the 

 granosphere is less advanced. A comparison of the two figures, 72 and 73, shows 

 that here, as elsewhere, the chromosomic process and the radiosomic process do 

 not run quite parallel, but that one may be in advance of the other. Thus in 

 73 the nucleus is further advanced than the nucleus of 72, but the cytosome of 72 

 is further advanced than the one of 73. 



Fig. 74. Spermatocyte, free and in the checkerboard stage. The fiber cones 

 are yet faintly traceable. Several rings of somosphere with accessory archo- 

 somes. An unusually small cell. 



Figs. 75 and 76. Spermatocytes, free, in the checkerboard stage. These two 

 figures represent two sections of the same cell. The numerous fiber cones have 

 not yet begun to recede. Several rings of somosphere with accessory archosomes. 



