162 A PHILOSOPHER WITH NATURE 



of any high degree of intelligence. They represent 

 rather the mechanism of mind in an early stage in 

 the evolution of life. The instincts in question are 

 always born with the animals ; but what is inherited 

 is not, as is sometimes imagined, knowledge or 

 ideas ; it is simply the physical organization, 

 common to a whole species, adjusted, often with 

 exquisite perfection, to respond more or less mechani- 

 cally to stimuli related to the average welfare of 

 the animal. Why the instinct often appears wonder- 

 ful to us is that we do not possess the same organiza- 

 tion, and that the stimuli to which it responds are 

 therefore often beyond the reach of our own senses. 

 A more noteworthy class of instincts than these 

 belong to a higher class. Most students of wild 

 nature in northern Europe, Asia, or North America 

 will have made the acquaintance of the wild duck 

 from which our common domestic duck is descended. 

 If this shy bird is surprised in the spring in sedge 

 or reeds with her young, she possesses a peculiar 

 habit which is interesting to watch, and about which 

 Darwin and Romanes held some difference of opinion. 

 I have many times witnessed the habit myself. If 

 one comes on the mother bird in wading through the 

 sedge, she first attempts to escape through the 

 cover without attracting notice. As soon as the eye 

 catches her, she is seen to be swimming rapidly in 

 front, followed by the brood of ducklings, the latter 

 packed together so closely that they seem to move 

 through the water behind her like a solid bank of 

 dark-brown fur. The moment the mother duck 

 perceives that she is seen, she springs clear out of 

 the water. Not, however, to fly away ; for, as you 

 see, she falls back, painfully flapping a broken wing, 



