HERRICK, Verve Components. 305 
We must know in detail the possible reflex pathways in 
the brain for all olfactory, visual, gustatory responses, etc., in 
the vertebrate type, and then on the basis of such a functional 
subdivision of the brain the problem of the mechanisms of 
higher cerebral processes may be attacked with a reasonable 
hope of success. The investigation of the internal organiza- 
tion of the brain may be pursued in several ways: 
I. The direct study of the human brain, both normal and 
pathological. On account of the enormous practical importance 
of neurology to both human psychology and pathology, re- 
search naturally turned directly to the human brain; but a more 
unfavorable starting point could not be found. 
II. It is now generally recognized that the complex hu- 
man brain can best be understood by finding first a simpler pat- 
tern such as is presented by one of the lowest vertebrates. Ac- 
cordingly the phyletic method has dominated all recent neuro- 
logical research. The brains of individual species are studied 
and monographed, particular attention being paid to the lower 
members of the vertebrate series in the hope of finding in them 
a schema or paradigm which can be followed upward through 
the comparative anatomical series and, after comparison with 
the ontogeny of higher brains, lead to a reconstruction of the 
phylogenetic history of the brain. While this method has been 
of great service, especially to such problems as can be ap- 
proached from the study of external morphology, it is im- 
mensely difficult when applied to the histological problems, and 
as a matter of fact has not as yet taken us very far. 
III. A third method, instead of taking an entire brain as 
the unit of research, concentrates attention upon a single func- 
tional system and seeks to get exhaustive comparative knowl- 
edge of it in many types. Starting with a fairly accurate and 
detailed knowledge of the functional systems at the periphery, 
we have simply to extend the lines of inquiry here blocked out 
for us. 
This gives a type of problem which is much more ap- 
proachable than the others. It is iiot so complex but more 
