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 hina in great terror, although no animal was in sight. 
“Tf,’”’ 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 
