14 TRUE TALES OE THE INSECTS. 



but they never become enormously abbreviated, and 

 always serve as sheaths or covers to the wings. They 

 are coriaceous or membranous, those of the males con- 

 stantly longer and narrower than in the females, and 

 always more transparent. The wings are large, and, 

 being well protected in rest, remain membranous, though 

 they often extend a little beyond the elytra ; the exposed 

 tip tends to become indurated. 



Atrophy of the Wings. 



There exist frequent cases, however, where the organs 

 are atrophied more or less, especially among the females. 

 The abbreviation is pushed the farthest in mantidae of 

 stick-like form, for a body excessively lank and long almost 

 precludes the power of flight, and condemns the species 

 which possess it to a pedestrian life (see Fig. 4), To these 

 insects flight would be possible only with wings of great 

 size, and the narrowness of the body does not permit the 

 muscles to enlarge sufficiently to move such organs easily ; 

 whereas the bigger mantidse of this shape have wings 

 always more or less undeveloped. 



But the females seem never entirely apterous ; on 

 the thorax always persists some trace of the organs of 

 flight. Thus among certain species (Coptopteryx) where 

 the elytra alone become developed to a rudimentary 



