342 TEXTBOOK OF ZOOLOGY 



various ways, millions of pounds being sold throughout the world. 

 Shellac is used for making varnishes and polishes, as an electrical 

 insulating material, in airplane construction, and many other ways. 



Insects serve as food for many fishes, amphibians, reptiles, birds, 

 and mammals, including man. It is important that insects be recog- 

 nized as playing a major role in this connection. Without the 

 insects the food habits of many of the vertebrates would be entirely 

 changed. 



Finally, many plants depend upon insects to assist in pollenizing 

 the blossoms. Only as the insect helps in transferring the pollen 

 from plant to plant or from the stamens to the pistil of the same 

 plant is it possible for some fruits, seeds, vegetables, and orna- 

 mental plants to develop. 



