1 62 BIOLOGICAL LECTURES. 



believe our present effort should be to agree upon a schema of 

 the vertebrate brain which, while not contravening the facts 

 of embryology, shall harmonize so nearly with the facts of 

 comparative anatomy as to facilitate rather than obstruct an 

 effort to describe and interpret the conditions encountered in a 

 given brain. 



I freely admit my ignorance or non-comprehension of certain 

 points, and also that my views have varied somewhat, particu- 

 larly as to the segmental value of the olfactory region of the 

 brain. Nevertheless, I regard myself as justified in advocating 

 the schema presented above upon the following grounds: (i) for 

 more than twenty years the general question has never been 

 long out of my mind; (2) with special reference to it I have 

 prepared and studied scores of brains of all classes and most of 

 the orders; (3) the subject has been discussed more or less 

 fully in papers by me upon the brains of many different forms; 

 (4) papers upon other forms l have been prepared at this insti- 

 tution; (5) the schema has proved practically available for 

 research, as indicated above, and has been readily compre- 

 hended and remembered by even general students. 



What I advocate is that there be recognized for the present 

 six definitive segments of the vertebrate brain under the titles 

 Rhinencephalon, Prosencephalon, Diencephalon, Mesencepha- 

 lon, Epencephalon, 2 and Metencephalon. It is my intention to 

 review the whole subject at the coming meeting of the Associ- 

 ation of American Anatomists in May, 1897. 



Practical Suggestions. As one of the older American 

 anatomists, and as having committed at least my full share 

 of terminologic errors, I venture to formulate some suggestions 

 of a practical nature for the benefit of the younger generation. 



Caution in Publishing New Terms. It is true that words 

 needlessly introduced into anatomy have no such embarrassing 



1 See papers by Clark, Mrs. Gage, Fish, Humphrey, Kingsbury, and Stroud. 



2 Even if Osborn is correct in his interpretation of the cerebellum as " primi- 

 tively " intersegmental ('88, 57), he nevertheless admits that it " secondarily 

 acquires a functional importance equal to that of the other segments." In Science, 

 Sept. 3, 1897, p. 373, I have asked information as to the origin of these and other 

 segmental names. 



