1915] Quantitative Entomology SN 
and nomenclature of colors require an entire reorganization. 
They should be primarily based on the nature of the color 
reflecting substance rather than on the physiological effect of 
the light rays that are most evident to the eye. This is neces- 
sary before we can make any progress in a quantitative state- 
ment of color values. The topographic differentiations or 
patterns are subject to the same classification that have been 
indicated for the surface modifications and doubtless are often 
responses to the same phylogenetic or ontogenetic causes. 
Internal structure may be divided into two chief divisions, 
the larger portion of the muscular and nervous systems whose 
‘specialization is definitely associated with details of the external 
structure and the remaining tissues associated with vegetative 
functions. 
The former should be considered in connection with the 
skeletal parts with which they are associated and their differ- 
ences in histological structure and in shape and size studied in 
relation to their functional requirements. When the study 
is carried far enough to. differentiate the various types of 
structure there will remain the ultimate distinctions to be made 
by quantitative determinations. 
The vegetative functions, digestion, respiration, circulation, 
excretion and reproduction, involve a series of structures 
having a more remote connection with the external environ- 
ment, but nevertheless, find their best basis of classification 
in the effect of the external world on their individual activities, 
and, of course, involves a full comprehension of the details of 
their physiology and has relatively little to do with the external 
topography except in its general aspects. 
All structures according to the conception here promulgated 
are classifiable into groups comparable with genera and species, 
the former distinguishable by differences of kind, the latter 
by differences of quantity. That descriptive entomology has 
before it the task of perfecting its nomenclature so as to be 
able to describe all differences of kind explicitly and accurately 
and then, by quantitative determinations can give exact descrip- 
tions of insect structure, a description which expresses the 
nature and character of the parts rather than their superficial 
appearance. 
