222 MICHAEL F. GUVER. 



this lack of favorable stages he says: "The whole organ was, 

 therefore, sectioned and in the great number of sections thus ob- 

 tained, not more than twenty cells were found in mitotic con- 

 dition." 



Wilcox continues: 'The few cases of mitosis observed were 

 in spermatocytes of the first order. One could easily distinguish 

 spermatogonia, spermatocytes of the first and second order, 

 spermatids, and numerous nearly mature spermatozoa. The 

 number of the latter to be seen was very large and precludes the 

 assumption that the testis was functionally impaired by age or 

 by hernia. In the opinion of the writer, this condition merely 

 indicates that all the various processes in the spermatogenetic 

 series are not necessarily to be observed as taking place at the 

 same time. I can see no reason why there might not become 

 established in the testis periods of cellular activity alternating 

 with periods of cellular rest." 



Unfortunately Wilcox gives no drawings with his paper nor 

 does he state definitely whether he regards the eighteen chro- 

 mosomes seen in the spermatocytes of the first order as the 

 reduced number or not. He does remark, however, that, "in 

 many cases they were plainly arranged in the tetrad or ring for- 

 mation which has been observed in a pretty general variety of 

 investigated species," consequently the inference would be that 

 a synapsis had occurred and that one might expect to find in 

 the neighborhood of thirty-six as the somatic number. 



The latest investigation on the number of chromosomes in 

 man with which I am acquainted is that of Duesberg ('06). 

 He reviews the work of Hansemann, von Bardeleben, and Flem- 

 ming and on the strength of his own observations concludes 

 that Flemming's count of twenty-four is correct. The excessive 

 number found by Hansemann he would account for on the basis 

 of the abnormal increase in the number of chromosomes which 

 is likely to occur in pathological tissues. In the case of Bar- 

 deleben he is inclined to believe that very thin sections (three 

 microns) are responsible for the smallness of the count since he 

 regards it as probable that part of the cell had been cut away. 



The tissue upon which Duesberg worked had been fixed in 

 Flemming's or in Hermann's fluid and stained by the iron-hat- 



