INSECT LIFE IN INDIA AND HOW TO STUDY IT. 



177 



the moults ; the form and proportion of the segments of the body, 

 especially of the thorax, undergo much change ; changes in colour occur 

 at the moults, and the integument becomes harder in the adult con- 

 dition. The wings in many are absent, and flight appears to be of 

 minor importance in the Order; in many cases, where the wings exist, 

 they are purely musical organs and are not of any use for flight. The 

 upper wings are never used for flight. The musical powers of the 

 Orthoptera are confined to the Sanatoria group. The Cursoria are 

 dumb or nearly so ; in this latter series the wings have little value for 

 flight, and are simply used for purposes of adornment or concealment, 

 and more especially so in the Phasmidae and Mantidaa (praying iusects 

 and stick insects). Here the upper wings frequently exhibit a great 

 resemblance to vegetable structures, such as stems, leaves, &c, the 

 veins and shape of the leaf being copied with remarkable accuracy 

 in the wing of the insect. Contrary to the usual conditions amongst 

 Insects, the female is often more remarkable in colouring than the 

 male. 



The eggs of the Orthoptera are deposited in capsules or cases ; 

 these capsules may contain only one egg or a great many (Figs. 

 9 and 12). 



The number of existing species of the Order is estimated at 

 10,000, but this is probably far under the mark, as the small tropical 

 forms have never been properly collected. 



We shall, following Sharp, treat the Order as comprising seven 

 families ; — 



1. Forfcculido? (earwigs) : upper wings short, 

 lower wings complexly folded ; body 

 armed at the extremity with a strong 

 forceps. 



2. Blattidce (cockroaches) : coxae of the legs 

 large, exserted, protecting the lower 

 part of the body. 



3. Mantidce (praying-insects) : front legs 

 very large, raptorial, armed with 

 spines. 



4. PhasmidcB (stick-insects) : meso-thorax 

 large as compared with the pro- 

 thorax. 



Series Cursoria. 

 Hind legs but little 

 different from the 

 others. 



