MAMMALS 69 



But would not those animals be in the best position 

 that had intelligence and instinct highly developed? 

 Will not an animal that makes instinctively for its prey 

 the moment it sees it, secure its object more speedily 

 and certainly than another that has to reflect on its 

 course of action ? 



It is true that instincts in connection with food and 

 escape might be so perfectly developed in mammals 

 that they would act with absolute precision when they 

 were needed. There are wasps that perform the most 

 complicated actions in laying their eggs, yet these are 

 all purely instinctive, as we shall see in the sixth 

 chapter. But instincts like these require the most 

 intricate nerve-tracks. 



Let us consider the complicated fashion in which 

 mammals seize their prey. Who has not seen how a 

 cat, at the sight of a mouse, steals forward, springs, 

 thrusts out its paw, seizes its victim, shakes it, and 

 finally devours it ? What elaborate nerve-tracks would 

 be required in it, if all this were instinctive ! yet there 

 are still other habits of the cat. In a word, we see that 

 if the complicated life of the mammals were effected 

 solely by instincts, the demands on the nervous system 

 would be so great as to leave hardly any room for 

 intelligence. 



We have only the two alternatives : either an 

 advanced intelligence or perfect instincts. In the 

 mammals it is the former that steadily advances, since, 

 as we saw, it can do more than instinct. We might 

 even say that the more sagacious animals are, the more 

 retrograde are their instincts ; and they are most 



