406 Evolution and Adaptation 
The protection of the young by their parents from the 
attacks of other animals appears to be a somewhat com- 
plex instinct, and it is interesting to note that the protection 
is extended to the young only so long as they are in need 
of it, and as soon as they are able to shift for themselves 
the maternal protection is withdrawn. 
The instinct of the young chick to seize in its beak any 
small moving object is a simple and useful reflex action, but if 
the object should happen to be a bee which stings the chick, 
another bee or similar insect will not be seized. Here we see 
that a reflex has been changed, and changed with amazing 
quickness. Moreover, the chick has learnt to associate this 
experience with a particular sort of moving object. It is this 
power to benefit by the result of a brief experience that is one 
of the most advantageous properties of the organism. 
Young chicks first show a drinking reflex if by chance 
their beaks are wet by water. At once the head is lifted 
up, and the drop of water passes down the throat. In this 
way the chick first learns the meaning of water, and no doubt 
soon comes to associate it with its own condition of thirst. 
The sight of water produces no effect on the inexperienced 
chick, and it may even stand with its feet in the water with- 
out drinking ; but as soon as it touches, by chance, the water 
with its beak, the reflex, or rather the set of reflexes is 
started. 
A more complicated instinct is that shown by the spider 
in making its web. In some cases the young are born from 
eggs laid in the preceding summer, and can have had, there- 
fore, no experience of what a web is like; and yet, when they 
come to build this wonderfully complex structure, they do so 
in a manner that is strictly characteristic of the species. 
The formation of the comb by bees, in which process, 
with a minimum of wax, they secure a maximum number of 
small storehouses in which to keep their honey and rear their 
young, is often cited as a remarkable case of adaptation. 
