?Ci^ 



THE FINER STRUCTURE OF THE SELACHIAN CER- 

 EBELLUM (MUSTELUS VULGARIS) AS SHOWN 

 BY CHROME-SILVER PREPARATIONS. 



By Dr. Alfred Schaper, 



Harvard Medical School, Boston, Mass. 



(With Plates I to IV and one Figure in the Text.) 



During my stay at the Marine Biological Laboratory at 

 Woods Hole, Mass., in the summer of 1897, I found opportu- 

 nity to extend my comparative anatomical studies on the cere- 

 bellum over the various species of Selachii to be found on that 

 coast. I especially endeavored, among other things, to eluci- 

 date by means of the Golgi method the finer structure of the 

 cerebellum of this group of vertebrates, so important from a 

 comparative anatomical standpoint. Notwithstanding the zeal 

 with which the various representatives of the vertebrate phy- 

 lum have been investigated by means of the Golgi method dur- 

 ing the last decade, the selachian brain has hitherto, strange to 

 say, scarcely been included within the range of research. The 

 first and only author so far who has given us a connected de- 

 scription of the histological structure of the selachian brain is, 

 as far as I know, E. Sauerbeck (4). The specimens at this 

 author's disposal were prepared by Professor Rudolf Burck- 

 hardt of Basel, under whose direction the work was prosecuted. 

 Sauerbeck's results appeared in an article in Band XII of the 

 Anatomischer Anzeiger under the title ''Beitriige sur Kenntniss 

 vovi feineren Bau des Selac/der/mns." Although this work, as 

 the author himself states, makes no claim to completeness, yet 

 it is the first attempt to fill in this existing gap in our compara- 

 tive histological knowledge of the central nervous system and 

 thereby can serve as a worthy starting-point for further and 

 more thoroucrh studies in this field. 



