104 THE MEANING OF EVOLUTION 
behavior on the second of February has no relation 
whatever to the weather we are to have later in the 
season. This is coming to be pretty generally under- 
stood. While the newspapers each year comment 
upon the groundhog and his shadow upon that day, 
year by year the notice has more of humor in it, and 
fewer people pay any attention to it. 
As for the backboned animals which are cold- 
blooded, these must, unless they are fish, give up the 
struggle completely, bury themselves in out-of-the- 
way places, and go worse than dormant. They often 
become absolutely cold and stiff. In the case at least 
of fish, it is quite possible for them to be frozen stiff, 
even to be enclosed in cakes of ice, and still to recover 
if the encasement is not too long continued. But 
the snakes, the turtles, the toads, the lizards, all 
are hidden beneath the ground waiting in abso- 
lutely unconscious rest the return of warmer 
weather. 
After the need for food and shelter comes the con- 
tinually recurring necessity on the part of almost 
every type of animal to escape from the unwearying 
persecution of higher creatures which would feed 
upon it. The whole creation is a constant network of 
animals which prey upon each other. It is the fate of 
a great majority of all creatures to fall victim to other 
animals to whom they serve as food. ‘Accordingly na- 
