Miscellaneous. 347 



produced lies a large lenticular ceiitrosome. After the formation of 

 the sphere of archoplasm a radiation proceeds from it. 



(5) After the concentration of the linin and chromatin the 

 membrane of the spermatogone nucleus disappears, and the nuclear 

 fluid mingles with the cytoplasm. The threads of the chromatin 

 granules lie close together. 



(6) The nuclei of the spermatocytes are much smaller than those 

 of the spermatogones of the last generation. The membrane of the 

 former is constituted afresh. 



(7) After the concentration of the archoplasm the larger portion 

 of the cytoplasm passes over into the same half of the cell, so that 

 the centrosome now lies in the plasmatic portion of the cell. 



(8) The number of the centrosoraes in the spermatocytes of the 

 first generation is from one to three. 



(9) The nucleolus always has an entirely peripheral position ; in 

 shape it is elliptical and compressed. The large chromatin granules 

 represent (though not alwaysj from one to two false nucleoli on the 

 opposite side of the nucleus. The true nucleolus never lies in the 

 interior of the linin-thread. 



(10) In the division of the centrosome the archoplasm also divides 

 before the nucleus, but immediately afterwards disappears from 

 view. 



(11) In the first spermatocyte division the nucleolus divides 

 either in the plane of the equatorial plate, together with the chromo- 

 somes, or outside this near one of the poles of the spindle. In the 

 latter case it passes out of the nucleus after the disappearance of 

 the nuclear membrane, but before the completion of the concentra- 

 tion of the chromatin granules (or before the formation of the 

 chromosomes). 



(12) The achromatin spindles do not disappear after the first and 

 second division of the spermatocytes. The second achromatin 

 spindle is developed independently of the first. It is possible to 

 isolate the eutire achromatin spindle from the cell. 



(13) In the division of the spermatocytes cytodieresis is not 

 simultaneous with the division of the nucleus ; in certain species of 

 spiders spermatids with four nuclei are first formed. 



(14) During cytodieresis the round " intermediate body " 

 (" Zwischenkiirperchen ") usually arises from the middle portion of 

 the spindle ; it may migrate anew into the body of the cell or 

 become constricted off from both daughter cells. The rest of the 

 spindle always remains in the spermatids until their transformation 

 into spermatozoa, forming a round body, which is not constricted 

 off from the spermatozoa until later. These remnants of spindles 

 (and intermediate bodies), which are always found in the testis 

 between the ripe spermatozoa, represent the " granules seminaux." 



(15) During the transformation of the spermatids into the 

 spermatozoa the nucleus becomes entirely homogeneous. The 

 whole of the chromatin gradually concentrates upon the nuclear 

 periphery, and the nucleus itself becomes converted into a vesicle. 

 SubstMpicntly the chromatin passes to one side of the nucleus as a 



