56 EISEN. [Vol. XVII. 



If we recapitulate the above, we find that the polymorphous 

 spermatogonia pass through the following stages : 



1. Perfect resting stage, in which the leaders are not yet 

 connected with the chromoplasts. 



2. Imperfect resting stage, in which the leaders are con- 

 nected with the chromoplasts. 



3. The various prophases of mitosis. 



4. Metaphase. 



5. Anaphase. 



6. Separation of the daughter-cells, 



7. A stage of growth, at the end of which the auxocytes 

 have been formed and attained their resting stage. 



Aiixocytes. 



The auxocytes are the most interesting of the various cells 

 in the testes of Batrachoseps, and a study of them is the prin- 

 cipal object of this paper. The name "auxocyte" was first 

 proposed by Arthur Bolles Lee for the large spermatogonia of 

 Helix pomatia, though strangely enough he did not himself 

 employ the name in his paper ('97) on this subject. As the 

 name seems useful, and as the cells in question are highly 

 characterized and exceedingly interesting, we can, I think, do 

 no better than to adopt it for cells of this class. By adopting 

 distinct names for the different varieties of the cells in the 

 testes, much of the existing confusion as to nomenclature will 

 be avoided. The auxocytes have previously been designated, by 

 respective investigators, as small spermatogonia, spermatocytes 

 of the first order, etc. ; but as all names relating to size are less 

 suitable, and as in this case the cells in question are not any 

 smaller than the large spermatogonia, the name proposed by 

 Bolles Lee is much to be preferred. 



The auxocytes are characterized by a bouquet stage and by 

 heterotypic mitosis. They are the only cells in the testes of 

 Batrachoseps which pass through this kind of mitosis. They 

 are the first cells to appear with twelve chromosomes, their 

 mother-cells, the round nucleated spermatogonia appearing with 

 twenty-four chromosomes. 



