86 ARTHROPODS 



cialized organs. But in spite of all this care many insects 

 perish every winter, and during severe winters nearly all 

 of certain species are killed. To offset this annual slaugh- 

 ter and to prevent annihilation by the ceaseless struggle 

 of the insect with his surroundings, the reproductive power 

 of nearly all insects is extremely great. Unless checked 

 by some agency almost any insect would multiply so rapidly 

 that it would, in a short time, become a serious menace to 

 the welfare of man. 



If the winter season should become longer and colder, 

 what would become of those animals that make little prep- 

 aration for it? How could they prevent this result? If 

 by circumstances an animal is driven into a region of longer 

 or more severe winter what would be the result? 



If the food supply of certain insects should become almost 

 exhausted, how could they still survive? 



If the enemies of a certain species of insect should be- 

 come weaker or more powerful, would it affect the insect ? 



What effect will this struggle with environment have on 

 the insect after it has gone on, generation after gentration 

 and year after year ? 



The larva of the honeybee which is snugly tucked away 

 in a cell, and fed with every delicacy which it could wish, 

 is covered over when it iias finished growing by a soft, tough 

 covering by the faithful workers. It would seem that this 

 would be sufficient, but it is not, for the larva spins above 

 its own head a weak, worthless fragment of a cocoon. 

 Why does it do this? If the cell and cover were not there 

 would it need this cocoon? If the cell were not there do 

 you think it would build a better cocoon? Does this sug- 

 gest anything of the past history of the bee ? 



