Some Points in tlio Spermatogenesis of Mammalia. 13] 



same conclusion, both he and Brown agree in exchiding tlie foot- 

 cells from any participation in spermatogenesis proper, believing tliem 

 to serve some subsidiary process in connection with it. eitlier mecha- 

 nical or secretory in nature. They conclude that the spermatozoa 

 arise from the small cells between the columns of preformed sperm a- 

 t(»zoa, and that they are successively regenerated from the primitive 

 stock by the process just alluded to, in the course of which phenomena 

 practically equivalent to akinesis play an important part. 



My own observations on these points are ftilly in accord with 

 theirs, and for the general outline of the facts and history of mammalian 

 spermatogenesis I would refer the reader more especially to Ebner's 

 work. Concerning the more minute features of the process, however, 

 the recent great advances in optical power and technique have ren- 

 dered it desirable, if not imperative, to revise and extend our know- 

 ledge in this direction; not only because at present we know practi- 

 cally very little of either the characters of the divisions or of the 

 remarkable constituents of the successive crops of cells, but also because 

 the recent splendid results obtained in the study of many invertebrate 

 spermatogeneses have rendered revision necessary, in order to make 

 comparison possible. 



The first direct attempt at the systematic study of the curious 

 accessory bodies appearing in the cells formed during course of mam- 

 malian spermatogenesis, was made by F. Hermann, who in 1889 pu- 

 blished^) an extremely interesting paper on these appearances in mice 

 and salamanders; although, as the author himself remarks, the work 

 is not complete, and while more recent investigation seems to neces- 

 sitate modification in the account he gave of the relation between the 

 archoplasm and the chromatic body, his paper, to my mind, will always 

 mark an epoch in our knowledge of minute cellular anatomy. The 

 present essay has grown out of it, and is intended to be a preliminary 

 contribution to a systematic study of the more minute features of 

 vertebrate spermatogenesis, which I intend to pursue in general. Al- 

 though the types examined were fairly numerous, consisting of dogs. 



Archiv für mikr. Anat. Bd. XXXTY. p, 58—102. 



9* 



