THE HEMIPTERA 39 



yields us the coloring matter, cochineal; and the tropical 

 Carter ia lacca from which we derive shellac. 



Lastly we must mention what are in some respects the 

 most disagreeable of the Hemiptera, the lice, many spe- 

 cies of which infest the lower animals and a few of which 

 are peculiar to man. Fortunately they are not so preva- 

 lent as formerly, as they are not tolerated very long by 

 people of the present average standards of cleanliness. 



The Hemiptera are remarkable for their great diversity 

 of form and habit. Active plant feeders, fierce assassins 

 of other insects, degenerate and almost shapeless parasites 

 of plants, denizens of the water, skaters on the surface 

 film of ponds and streams, and the despised parasites of 

 the human body, they nevertheless show certain features in 

 common which indicate their kinship. 



