94 INSTINCTIVE BEHAVIOUR 
worms with an avidity which looks like an inherited recog- 
nition of natural food. Pheasants and partridges also appear 
to be specially affected by worms, and when one of them 
seizes a worm for the first time, he shakes it and dashes it 
against the ground. Chicks, a week or ten days old, also seize 
a largish fly or bee with a dash, and maul it on the ground, 
throwing it on one side before again approaching it. And 
such birds seem to show an instinctive tendency to bolt with 
such treasures as caterpillars or small worms. Moor-hens 
cannot at first be induced to take food from the ground. It 
has to be held above them, whereupon they crouch down, with 
head and neck held back, opening their beaks more like the 
callow young of nursling birds; but they also strike upwards 
at the object—these modes of behaviour being, no doubt, 
correlated with the manner in which the mother moor-hen 
normally feeds her young from her beak during the early days 
of life. Callow fledglings, such as young jays, simply open 
their mouths, gaping widely to be fed. And many will 
respond in this way to such a note as a low whistle, as may 
readily be seen with swallows. But at a later age such birds 
show instinctive modes of reaction of a more complex type. 
A jay, for example, was offered a summer chafer or June bug, 
seized it at once in his bill, and tried to place his foot on it. 
Then he hopped down on to the floor of his cage, dropped the 
beetle, seized it again as it crawled off, and after two or three 
attempts swallowed it, tossing it back from the point of his 
bill into the throat. This was the first time he took food 
from the ground or swallowed it in this manner. 
On the whole, there seems to be much inherited definiteness 
of co-ordination, and some tendency to respond in a definite 
manner to specific stimuli. That there should not be more 
differentiation in this respect than observation discloses is 
probably due to the fact that the parent birds afford, under 
natural conditions, so much guidance in the selection of food. 
Since the solitary wasp unerringly seizes its appropriate food, 
since it responds instinctively to specific stimuli, there would 
seem no reason why birds should not show similar instinctive 
