FLIES. 139 



There is another most interesting family of 

 flies, called the gall gnats. They may be gener- 

 ally known by their slender bodies, hairy wings, 

 with only two or three longitudinal veins, and 

 long antennae, jointed and beaded like a necklace, 

 each bead surrounded by a whorl of bristles. 

 Although the majority of the species are extremely 

 delicate and minute, they perform greater won- 

 ders than any other kind of diptera. 



With few exceptions, the food and home of 

 their larvs is in the living tissue of plants, and it 

 is also a curious fact that the different species of 

 the perfect fly visit exclusively a certain kind of 

 herb, bush, fruit or flower, on which to lay their 

 eggs. 



The peculiar irritating, poisonous nature of 

 these maggots, as soon as they are hatched, and 

 have penetrated a leaf or stem, produces various 

 and oftentimes fantastic deformations, which are 

 sure to arrest the attention of those who have 

 eyes to see the curious things in nature. On the 

 leaves of many kinds of trees and shrubs, these 

 galls appear in the forms of knobs, buttons, blis- 

 ters, cockscombs, etc., frequently covered with a 

 pubescence or short, soft down, like that of the 

 peach, and of various colors. The premature pur- 

 ple of the gooseberry, and the red of the currant, 

 sometimes is the work of a single little gall-fly 

 maggot lodged within, and living on the putrid 



