122 THE EVOLUTION OF INSTINCT 



passed on. Hudson gives among other illustrations of this 

 fact an account of some English sparrows which he was 

 accustomed to feed from a window. "The bread and seed 

 were thrown on to a low roof just outside the window, and I 

 noticed that the young birds when first able to fly were al- 

 ways brought by the parents to this feeding place, and that 

 after two or three visits they would begin to come of their 

 own accord. At such times they would venture quite close 

 to me, showing as little suspicion as young chickens. The 

 adults, however, although much less shy than birds of other 

 species, were extremely suspicious, snatching up the bread 

 and flying away; or, if they remained, hopping about in a 

 startled manner, craning their necks to view me, and mak- 

 ing so many gestures and motions, and little chirps of alarm, 

 that presently the young would become infected with fear. 

 The lesson was taught them in a surprisingly short time; 

 then suspicion was seen to increase from day to day, and 

 about a week later they were scarcely to be distinguished 

 in behavior from the adults. It is plain that, with these 

 little birds, fear of man is an associate feeling, and that, 

 unless it had been taught them, his presence would trouble 

 them as little as does that of a horse, sheep, or cow." 



The large Rhea of South America which is used for food 

 and must have been hunted by savages for a very long period 

 should certainly show a strong innate fear of man, but Hud- 

 son found that the young captured just after hatching would 

 follow him about in perfect confidence. When he would 

 imitate the danger note of the parents the young would rush 

 to him in great terror, although no animal was in sight. 

 "If," says Hudson, "I had caused a person to dress in white 

 or yellow clothes for several consecutive days, and had he 

 shown himself to the birds, I have no doubt that they 

 would soon have acquired a habit of running in terror from 



