120 MEMORY, HABIT, AND IMITATION 



generally instinctive : it pursues the same 

 lines throughout all the individuals of the 

 species. All birds of a kind tend to build their 

 nests according to a common plan, and are ac- 

 tuated by similar home-staying or migratory im- 

 pulses. Wild animals that are caged continue to 

 act as if the earth were below and the sky above 

 them : squirrels will make believe to bury nuts : 

 mateless birds will collect nesting materials as 

 spring approaches. Domesticated animals, on the 

 other hand, appear to possess a special aptitude 

 for forming, individually, habits of their own : 

 horses become used to riding or driving, and 

 resent a change of service : dogs accommodate 

 themselves to the domestic arrangements of 

 their masters. It is, indeed, owing to this plas- 

 ticity that they have been domesticated at all. 

 Amongst wild animals behaviour which we speak 

 of as habitual is very frequently instinctive. A 

 tiger, after killing its prey, does not eat it forth- 

 with, but lies up, near by, for some hours before 

 commencing its meal conduct which assists 

 very greatly the sport of tiger shooting. This 

 peculiarity is instinctive not habitual : it runs 

 throughout the species. By instinct, not by 

 habit, birds put their heads under their wings 

 when sleeping: the penguin pretends to do so, 

 although its degenerate wings afford no cover. 

 A dog turning round before settling itself to sleep 

 is also acting instinctively, not by force of habit : 

 dogs, generally, preserve this survival from the 

 past. 



Can habit produce changes which become 

 innate and hereditary? Has man radically im- 

 proved his nature by the practices of civilization ? 

 Are we born more decent, more orderly, more 



