No. I .] SPERM A TOGENESIS OF BA TRA CHOSEPS. i 1 5 



Fig. 106. Spermatocyte in the confluent stage, but the confluence is not yet 

 perfect. The polar cones are mostly gone and the archosomes so faint as to be 

 indistinct. The new cell membrane has formed along the equator of the central 

 spindle. The latter has contracted, several of its fibers being beaded. Many 

 plasmospheric granules along the new membrane, especially on the left side. 



Fig. 107. Spermatocyte in the perfectly confluent umbrella stage. The cells 

 are almost separated and are only connected with each other by the central 

 spindle. The spindle is greatly contracted, showing some beaded fibers. No dis- 

 tinct archosomes, and the polar cones have so descended into the nucleus as 

 to be no more visible. A false nuclear membrane is being formed around the 

 nucleus. The pole of the lower spindle is just above the nucleus ; at the apex is 

 a small archosome. In the upper cell is a large accessory archosome. 



Fig. 108. Spermatocyte in the end of the confluent stage, the chromosomes 

 just beginning to reappear in the chrysanthemum stage. The cytoplasmic mem- 

 brane is fully formed around the nucleus, and is now being pulled away by the 

 centrosomes. The granospheres are being reconstituted around the poles of the 

 spindle. Parts of the plasmospheres are seen along the new cell walls. A mid- 

 body on the central spindle, which latter has been greatly contracted. The poles 

 of the central spindle are connected \\-ith the cytoplasmic membrane by a few 

 fibers. 



Fig. 109. Spermatid. In a rather advanced stage of development, the nucleus 

 having assumed its full size. The two spheres have been reconstituted. An 

 archosome is seen to the left of the granosphere. The nucleus is in the checker- 

 board stage. Several paracellular bodies are attached to the exterior of the cell. 

 These are probably expelled particles of the spheres, which have become inflated. 

 They show in their interior a fibrous structure. There are two distinct chromo- 

 plasts in the nucleus, recognizable by their endochromatic granules. The remains 

 of a spindle bridge at the upper pole of the cell. 



Fig. I id. Auxocyte. Detail figure of one of the central spindle poles, show- 

 ing the formation of the contractile fibers and their connection with the somo- 

 sphere of the archosome. In the center of the field is seen a large archosome 

 consisting of a darkly stained inner centriole and somosphere, surrounding which 

 is a large unstained centrosphere. Twelve fine bars connect the centriole with 

 the contractile fibers which begin on the outer margin of the centrosphere. On 

 the upper ends of the centrosphere only the ends of the contractile fibers are 

 seen. Several accessory archosomes in a ring around the archosome. The red, 

 granular plasma, divided in three groups, is the remains of the plasmosphere. 

 Each accessory archosome possesses a centrosphere. The contractile fibers are 

 strongly beaded. 



Fig. III. Auxocyte. Detail figure of a pole of the central spindle, showing 

 the archosome and its connection with the central spindle fibers and the con- 

 tractile fibers. The archosome is large and contains two centrioles, each sur- 

 rounded by a somosphere. Several accessory archosomes, one of which appears 

 to be the starting point of a contractile fiber. The contractile fibers are strongly 

 beaded. Zeiss Apo. 2 mm., Apert. i, 40, Oc. iS. 



Fig. 1X2. Auxocyte. Detail figure of an archosome; the contractile fibers 

 start from the outer margin of the centrosphere. The chromosomes are in the 

 anaphase, with the contractile fibers greatly contracted. They are strongly 

 beaded, the beads being situated between a covering of granulated fibers, evi- 



