76 EISEN. [Vol. XVII. 



have again reunited and to be situated very much as in the 

 resting stages of the earlier cells, and it is more than probable 

 that this reuniting takes place in the umbrella stage of the 

 spermatocyte. My observations upon this point are only frag- 

 mentary and few, and the above is merely a suggestion to 

 guide future observations. 



I have already, in another place in this paper, referred to the 

 fact that in the very earliest beginning of the bouquet stage 

 the free ends of the leaders point to the two spheres, and that 

 it is possible that one or both of the spheres have some influ- 

 ence over the ends of the chromosomes. These ends actually 

 rest on the nuclear membrane, but do not penetrate it. For 

 the formation of fhe leaders, see the part under the heading 

 Leaders, pages 42, 43. 



Equation or Reduction ? — According to the foregoing de- 

 scriptions there is no reduction in the testes of Batrachoseps, 

 at least not in the sense of Weismann. The only reduction 

 is in the number of the chromosomes, which are reduced from 

 twenty-four in the polymorphous spermatogonia to twelve in 

 the auxocytes. Both the heterotypic and the homoeotypic 

 mitosis, as has been so conclusively shown by Flemming and 

 Meves, accomplish the division of the chromosomes by equa- 

 tion and not by reduction. The splitting of the chromosomes 

 is first accomplished, and later on, when the chromosomes have 

 been placed on the spindle in the shape of bretzels, the separa- 

 tion takes place in such a way as to leave a part of the chromo- 

 plast attached to each daughter-chromosome, showing plainly 

 that an equation has taken place. In Figs. 121 and 122 I have 

 endeavored to illustrate this equation division. The chromo- 

 plasts are marked by a C, showing that they also are divided. 

 As regards the homoeotypic mitosis there is even less room for 

 a reduction. In Figs. 118 and 120 this mitosis is represented. 

 These figures have been drawn from actual chromosomes and 

 are not diagrammatic, like those represented in Figs. 121 and 

 122. As Meves has lately discussed this subject it will suffice 

 to state that my own observations fully corroborate his. 



Halting Stages in the Mitosis. — There are certain stages in 

 the mitosis which are of much longer duration than others, as 



