112 EI SEN. [Vol. XVII. 



The chromomeres are seen to be of different sizes and to contain a variable num- 

 ber of from nine to three chromioles each. 



Fig. 77. Spermatocyte, free and with chromosomes in the checkerboard 

 stage. The chromomeres are well separated and contain about three to nine 

 chromioles each. The spheres are being reconstituted together, the inner one 

 being the granosphere and the outer one the plasmosphere. An archosome -with 

 two centrioles on the plasmosphere. The fiber cones have not yet disintegrated, 

 the upper one with a distinct accessory archosome at the apex. 



Fig. 78. Spermatocyte, free and with the chromosomes in the chrysanthemum 

 stage. The chromomeres are much separated, though the staple-shaped form of 

 one of the chromosomes is distinct. The spheres are reconstituting in the upper 

 left corner of the cell. Accessory archosomes connected by a ring of somo- 

 sphere. The remains of the fiber cones are recognizable in the four projecting 

 corners of the cell. A linin network is stained reddish. 



Fig. 79. Spermatocyte, free, the chromosomes in the beginning of the con- 

 traction stage or the third prophase. All traces of fiber cones have disappeared. 

 The spheres are being reconstituted, the darkly stained one being the granosphere. 

 Numerous accessory archosomes in the plasmosphere. 



Fig. 80. Spermatocyte, free and the chromosomes in the beginning of the con- 

 traction stage. The two spheres are being reconstituted. Numerous accessory 

 archosomes on the plasmosphere. Figs. 80-82 are in very much the same 

 stage of development, but representing a serial development and contraction of 

 the chromosomes. In Figs. 81 and 82 the plasmosphere is reconstituted in the 

 opposite end of the cell from the granosphere. This is frequently the case in the 

 spermatocyte, and saves the redistribution of the sphere to the equatorial of 

 the new spindle. 



Figs. 81 and 82. See Fig. 80. 



Fig. 83. Spermatocyte. Contraction stage in which the chromosomes are 

 again assuming their staple form, and in which the linin network is separating 

 from the chromosomes. This stage corresponds to the bretzel stage of the auxo- 

 cytes. Figs. 83 and 84 are in nearly the same stage. The plasmosphere is recon- 

 stituted in the opposite part of the cell from the granosphere. Numerous acces- 

 sory archosomes around the granosphere. The similarity of all is so great that it 

 cannot be decided which of them is the archosome. Chromomeres show the 

 interior chromioles. 



Fig. 84. See Fig. 83. 



Fig. 85. Spermatocyte in the beginning of the angular chromosomes, the 

 fourth prophase. The chromosomes have become narrower and the margins are 

 more even. This stage corresponds to the angular segments of the auxocytes, 

 though there are some important differences. The chromoplasts, for instance, are 

 very prominent in the auxocyte, while in the spermatocyte they are only now and 

 then to be distinguished from the chromosomes. Only a few of the chromosomes 

 are figured. At the lower margin of the cell are seen the spheres, but it is doubt- 

 ful if the round mass is anything but the plasmosphere. The linin network is 

 disintegrated and retracted from the chromosomes. Several of the superfluous 

 archosomes have been expelled from the cell and are now seen attached to the 

 exterior of the cell wall. They have also swelled up and increased perhaps five- 

 fold in size, but to what extent their inner structure has become modified by the 

 swelling up is not clear. It seems, however, most probable that the somosphere 



