THE EVOLUTION OF INSTINCT 117 
as before said, little more than anticipatory touch; visual im- 
pressions are, in all these creatures, habitually followed by 
tactual ones. But tactual impressions are, in all these crea- 
tures, habitually followed by contractions. ... From the 
zoophytes upward touch and contraction form an habitual 
sequence; and hence, in creatures whose incipient vision 
amounts to little more than anticipatory touch, there con- 
stantly occurs the succession—a visual impression, a tactual 
impression, a contraction.” This habitual association will 
link the two responses so that a contraction will follow 
immediately upon the visual stimulus. The effect of such 
experiences accumulated by heredity generation after 
generation is to establish a new congenital response which 
is of value to the species. With increased power of sensory 
discrimination the visual stimuli produced by smaller objects 
whose contact does not cause a protective contraction, but 
rather the activities of food taking, may in a similar manner 
become associated with movements of prehension, thus 
enabling the animal to react in different ways to objects at a 
distance. In this way Spencer supposes instincts to have 
been built up by growing out of simple reflex acts instead of 
being the outcome of a lapsed intelligence. Spencer’s 
conception is more congruous with the general doctrine of 
psychic evolution and does not involve the assumption that 
the lower we go in the animal kingdom the more purely 
intelligent the actions of animals become. 
The theory of Spencer, which was putforwardin 1855, is 
based entirely on the assumption of the transmission of 
acquired characters like so many other of his psychological 
speculations. After the ‘Origin of Species” was published 
Spencer accepted the theory of natural selection, but as- 
signed to it a subordinate réle, especially in the evolution 
of mind. 
