138 Wisco7isin Academy of /Sciences, J.rfe, and Letters. 



SUGGESTIONS AS TO A BASIS FOE THE GRA- 

 DATION OF THE VERTEBRATA.* 



BY T. C. CHAMBERLIN, A. M., 

 Professor of Natural Science in the State Normal School, Whitewater. 



Some of the leading principles stated in tliis scheme have 

 been advanced by others, and form important considerations 

 in the several classifications advocated by our leading natural- 

 ists, yet the author has seen no systematic scheme embodying 

 them as a basis for gradation as distinguished frora classificatio7i, 

 and some of the principles have not, to his knowledge, been 

 previously stated. To whom credit is due in reference to par- 

 ticular facts or principles cannot readily be stated. The author 

 advances it with deference, because he cannot command that 

 multitude of facts that are necessary to establish the claims of 

 any system in zoology. Great difficulties arise to the amateur 

 student away from the great libraries from the state of zoolog- 

 ical literature, and under any circumstances from the want of 

 sufficiently full and accurate observations on the nervous sys- 

 tem. It is not intended to advance assertions, but suggestions. 

 The suggestions here made, if of value at all, may be of value 

 beyond the vertebrata. 



This scheme differs from most others in being founded on a 

 single organism, the nervous. This, at first thought may seem 

 a fatal objection. But it must be remembered that there 

 should be a clear distinction drawn between ra^ih and classifi- 

 cation. It will doubtless be conceded that a cephalopod ranks 



* This Hubject was originally presented to the Academy in the extemporaneous style 

 from notes and diasrrams. The notes, which were not closely followed, constitute the 

 abstract which appeared in the Bulletin. As it is impossible now to reproduce the 

 actual presentation, and as it ia of no importance in preparing this article for publica- 

 tion here, I have taken all the liberties of original presentation. 



