74 THE EVOLUTION THEORY 



the nose, neither attempted to escape nor showed any hostilit}^ to 

 man, Ijut quietly let itself be caught. Similar tales were told by 

 Steller in 1799, after he had been obliged to pass a winter with 

 his sailoi's on an island in the Behring Straits. The numerous 

 gigantic sea-cows (Bhytiiia deUeri) which lived there were so con- 

 fiding that they allowed the boat to come quite up to them, and 

 the sailors were able to kill many of them from time to time, 

 usinp; their flesh for food. But towards the end of the winter 

 the animals began to be shy, and, in the following winter, when 

 other sailors to the polar regions endeavoured to hunt them too, it 

 was very difficult to secure them ; they had recognized man as an 

 enemy, and fled from him when they saw him from afar. Thus 

 the same individuals which had earlier carelessly allowed man to 

 come up to them now avoided him as an enemy. T}il>< tvas not 

 inbtinct, it 'was a behaviour controlled by the 'will and founded on 

 exijerieiice. But it would soon become ' instinctive ' if the meeting 

 with the enemy were often repeated, just like the winding-up of 

 a watch, which is often done at a wrong time, for instance, on 

 changing clothes during the day, and thus without reflection. It 

 is quite easy to conceive that if the material brain -adaptation which 

 causes flight without reflection at the sight of man were transmissible, 

 the flight-instinct might become a congenital instinct in the species 

 in question. But this assumption is unfounded ; for, as is shown 

 by the case of the sea-cow, we do not require it where the animal 

 is of sufficient intelligence to perform by its own discernment the 

 action necessary to its existence. The action may thus become 

 ' instinctive ' through exercise and imitation in the individual life, 

 without however attaining to transmissibility. 



But in many cases this is not enough, namely, in all eases in 

 whicli the degree of intelligence is not sufficiently high, or where 

 the flight movement must follow so rapidly that it would be too 

 late if it had to be regulated by the will, as, for instance, the shutting 

 of the lids when the eye is threatened, or the flight of the fly or the 

 butterfly when an enemy approaches. Both fly and butterfly would 

 be lost in every case if they had voluntarily to set the flight-move- 

 ment going after they became conscious of danger. If they had 

 first of all to find out from whom danger threatened no individual 

 would escape an early death, and the species would die out. But 

 they possess an instinct which impels them to fly up with lightning- 

 speed, and in an opposite direction, whenever they have a visual 

 perception of the rapid approach of any object of whatever nature. 

 For this reason they are difficult to catch. I once watched the 



