[THE EVOLUTION OF ORGANIC BEHAVIOUR 35 
he brain is the organ of conscious control, granting that it 
‘an receive impulses from and transmit impulses to the reflex 
‘entres, no more is here implied, and no more can be legiti- 
nately inferred, than that the kind of organic behaviour we 
‘all “reflex action” is in the higher animals in touch with 
the guiding centres. We have no ground for assuming that 
n reflex action there is any power of intelligent guidance 
ndependent of that which is exercised by the brain or 
malogous organ. In brief, reflex acts, in animals endowed 
vith intelligence, may be regarded as specialized modes of 
wrganic behaviour; which are in themselves often charac- 
verized by much complexity ; which subserve definite biological 
mds; which are effected by subordinate centres capable of 
ransmitting impulses to, and receiving impulses from, the 
sentres of intelligent guidance; and which, as responses con- 
ined to certain organs or parts of the body, form elements 
in the wider behaviour of the animal as a whole. 
VI.—THE EvoLUutTion OF ORGANIC BEHAVIOUR 
The interpretation of organic behaviour in terms of evolu- 
sion mainly depends on the answer we give to the question : 
Are acquired modes of behaviour inherited? A negative 
uswer to this question is here provisionally accepted. But 
ihe premisses from which this conclusion is drawn are too 
sechnical for discussion in these pages. It must suffice to 
state as briefly as possible what this conclusion amounts to, 
md to indicate some of the consequences which follow from 
ts acceptance. 
The fertilized egg gives origin, as we have seen, to the 
nultitude of cells which build up the body of one of the 
nigher animals. There are, on the one hand, muscle-cells, 
rland-cells, nerve-cells, and other constituents of the various 
issues; and there are, on the other hand, the reproductive 
ells—ova or sperms, as the case may be. Now, every cell in 
hhe developed animal is a direct descendant of the fertilized 
‘gg. But of all the varied host only the reproductive cells 
