43 2 THE STUDY OF INSECTS. 



Not only are the legs of crane-flies poorly fitted for loco, 

 motion, but they are so feebly attached to the body that 

 they are easily broken off ; however, the loss of a few legs 

 does not seem to be a serious matter to one of these insects. 

 Yet from what we know of the laws of development we are 

 forced to believe that the peculiar form of the legs has been 

 attained in order to fit them to perform better some impor- 

 tant function. It may be that the great length of the legs 

 is correlated with the unusual length of the abdomen and 

 ovipositor, and enables the insect to oviposit in a better 

 manner than would otherwise be possible. When about to 

 lay her eggs, the female stands nearly upright and, bringing 

 the abdomen at right angles to the surface of the earth, 

 thrusts the ovipositor into the ground. After placing one 

 or two eggs in the hole thus made, she moves forward a few 

 steps and repeats the operation. 



Family Blepharocerid^e (Bleph-a-ro-cer'i-dae). 

 The Net-winged Midges. 



The net-winged midges are extremely remarkable in- 

 sects; for in certain respects the structure of the adults is 

 very peculiar, and the larvae appear much more like Crusta- 

 ceans than like Insects. 



The adults are mosquito-like in form ; but they differ 

 from all other insects in having the wings marked by a net- 

 work of fine lines which extend in various directions and 

 are not influenced at all by the veins of the wing (Fig. 506) ; 

 they are, however, quite constant in their position in the 

 species that we have studied. 



When a wing is examined with a microscope, the fine 

 lines are seen to be slender thickenings extending along the 

 courses of slight folds in the wing. The significance of 

 these folds is evident when a net-winged midge is observed 

 in the act of issuing from its pupa-skin. When the wing is 

 first pulled out of the wing-sheath of the pupa, that part of 



