CHROMOSOMES OF HUMAN SPERMATOCYTES 9 



the remainder seven clnoniosonics." .... I have seen no evi- 

 dence of any kind of such a i)airinj>; of chi-oniosonies in the second sper- 

 matocytes, neither in my own material nor in that received by Guyer, 

 although I have examined fully two hundred division stages of these 

 cells. Of decisive value are such cases, of which several are figured 

 by me, where all the chromosomes can be distinctly seen on lateral 

 views of spindles of the second maturation. The only explanation 

 I can offer for this conflict of opinion is that Bardeleben and Guyer 

 either employed too intense staining of their sections, or else studied 

 cells in which the chromosomes had been greatly swelled by fixation 

 and hence not clearly distinguishable. 



I might ssiY in passing that my own observations lead me to 

 agree wdth Montgomery's explanation of the so-called second 

 reduction. 



Von Winiwarter ('12) used for his study of human spermato- 

 genesis sections of testis of four men (presumably white) aged 

 21, 23, 25 and 41 years, all which seemed to be free of any venereal 

 taint or infection. He states that the material was well fixed 

 and offered abundant opportunity to study chromosomes un- 

 der favorable conditions. He does not state how soon after 

 death the tissues were fixed in the weak Flemming, modified 

 by Meves, which he used. 



As to the number of chromosomes in the spermatogonia he 

 states (p. 130), ''In 32 plates I count 47 chromosomes 29 times, 

 4b chromosomes 2 times and 49 once." A careful study con- 

 vinces him that 47 is the bivalent number in man. It may be 

 noted that he also found occasional plates containing 65, 70, 86, 

 etc., up to 100 and 150. These he considers in the nature of 

 exceptions common to the germ cycle of all animals. 



In the nucleolus of the resting stage, he finds an acid staining 

 nucleolus (plasmosome) and an elongated bacilliform, basic 

 staining body, the chromatin nucleolus or accessory chromosome, 

 which lies close to the nuclear membrane. In the prophases 

 of the primary spermatocyte the accessory chromosome show^s 

 no evidence of duality in structure. The remaining chromosomes 

 showed a pronounced bivalent appearance. In the majority 

 of cases he finds 24 chromosomes, only one of wdiich, the ac- 

 cessory, fails to divide in the ensuing division of the first 

 spermatocyte. 



