No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 113 



has filled out the centrosphere, and that the centrioles have separated from each 

 other. 



Fig. 86. Spermatocyte in the angular chromosome stage. This and the previ- 

 ous figure are very much in the same stage as regards the nucleus. The spheres 

 are not distinct and there are no expelled archosomes. Three accessory archo- 

 somes at the upper part of the cell. 



Fig. 87. Spermatocyte in the beginning of the knotted chromosome stage. 

 The chromosomes are separated and. have not yet accumulated in the center of 

 the cell. Numerous accessory archosomes, each one surrounded by an amoeboid 

 centrosphere. A very small granosphere. Chromioles are seen in the chromo- 

 somes. 



Fig. 88. Spermatocyte in the knotted chromosome stage. A distinct grano- 

 sphere, a scattered plasmosphere, and numerous accessory archosomes in the 

 cytoplasm. Some of the archosomes are being expelled from the cell. Chromi- 

 oles are seen in the chromosomes. 



Fig. 89. Spermatocyte in the knotted chromosome stage. Several fiber 

 cones are yet seen, and it is probable that two of them will form the central spin- 

 dle. Numerous accessory archosomes on the fibers of the cones, some of the 

 fibers evidently dissolving the nuclear wall. 



Fig. 90. Spermatocyte in the knotted chromosome stage. The nuclear mem- 

 brane is completely dissolved by two fiber cones. The individual chromosomes 

 are so tightly knotted that they are difficult to segregate one from the other. 

 The chromosomes are only approximately correctly figured. These two fiber 

 cones are probably the beginning of the central spindle. A sphere is seen in the 

 upper apex of the cell ; many accessory archosomes and an archosome with an 

 amoeboid centrosphere. 



Fig. 91. Spermatocyte in the knotted chromosome stage. Only a few chro- 

 mosomes are seen in the section. The nuclear membrane has been dissolved by 

 the fiber cone emanating from the upper apex. The linin network is scattered 

 and the granules are mixing with the cytoplasm. Accessory archosomes on the 

 fibers and one at the lower pole of the cell. Each one is furnished with an amoe- 

 boid centrosphere. Some of the chromioles in the chromosomes are distinct. 



Fig. 92. Spermatocyte in the F'-stage ; the chromosomes are in the center of 

 the cell. Only one pole of the central spindle is developed, there being no trace 

 of the other pole. The nuclear membrane is dissolved. A plasmosphere to the 

 left of the future equator. A dividing archosome in the pole of the spindle. 



Fig. 93. Spermatocyte in the beginning of the F'-stage, the chromosomes being 

 in the center of the cell. A central spindle is being formed out of two old fiber 

 cones. At the apex of each cone is an accessory archosome which is now assum- 

 ing the function of an archosome. 



Fig. 94. Spermatocyte. Chromosomes in the knotted stage, but the central 

 spindle has already formed out of two opposing fiber cones. This is the charac- 

 teristic form of the spindle in this stage, the two poles being greatly depressed. 

 An archosome at each pole. There is no distinction between the mantle fibers 

 and the central spindle fibers. I found several cells like this one, but no interme- 

 diate stages with Fig. 93. 



Fig. 95. Spermatocyte. In the F-stage, not yet in the metaphase. The 

 upper pole with several accessory archosomes, one of which is the spindle archo- 

 some. The lower pole has probably been cut off by the knife. 



