I40 Journal of Comparative Neurology. 



INTRODUCTION. 



This investigation was made in the anatomical laboratory 

 of Cornell University. I am glad to acknowledge my in- 

 debtedness to the Anatomical Department for the material and 

 facilities placed at my disposal: To the members of the De- 

 partment, and particularly to Prof Wilder and Dr. Fish under 

 whose immediate supervision the work was done, I wish to ex- 

 press my appreciation of their interest manifested in it ; the 

 former put into my hands all his unpublished notes and draw- 

 ings as well as numerous preparations of the brain made in 

 1873 and 1874. To Prof Gage I am under deep obligation 

 for material kindly obtained for me from Prof V/hitman of 

 Chicago University and for suggestions as to methods. The 

 series of sections through the brains of Dieinyctyhis and Desino- 

 gnathus^ which I have been enabled to examine by the kindness 

 of Mrs. Gage and Dr. Fish have also been of great service to 

 me. Numerous valuable suggestions have been gained from 

 the discussions of the Neurological Conferences. 



It is somewhat surprising that, although extended investi- 

 gations have been made upon the nervous system of various 

 urodeles by numerous anatomists, neither the brain of Nectiirus, 

 nor, indeed, that of its European relative, Proteus, have re- 

 ceived more than a very fragmentary treatment. The import- 

 ance of these forms is obvious and has been recognized in the 

 attention given to other parts of their structure. They are the 

 lowest Amphibia, generally so regarded, and their perenni- 

 branchiate condition suggests at least the presence and 

 persistence of what in other forms are larval peculiarities 

 merely. Further, Necturus presents in its availability and the 

 convenient size of its brain, — neither too large for convenient 

 microscopic examination nor too small for macroscopic obser- 

 vation, — characters making it also well suited for the elucida- 

 tion of the numerous problems connected with the amphibian, 

 and particularly the urodele, brain. Therefore a somewhat 

 complete treatment of this form would seem desirable. 



