HEMIPTERA : CHARACTERS. 361 



along the breast, often reaching to or even extending be- 

 yond the base of the hind legs ; when employed it is pro- 

 truded forwards. 



All the insects belonging to this order undergo a series of 

 moultings, analogous to those of other insects, although less 

 in degree. They are produced from eggs as small, active, 

 six-legged larvae, having nearly the resemblance of the 

 perfect insects, but entirely destitute of wings or wing- 

 covers. After shedding the skin several times, gaining 

 thereby only an increase of size, they appear as pupae, but 

 still active, and differing only from the larva) in having the 

 wings and wing-covers concealed in small cases placed upon 

 the back. Another moulting brings them to the imago 

 state, in which their wings are fully developed. In the 

 apterous, or wingless species, the transformations merely 

 consist in a gradual increase of size at the successive moult- 

 ings. The pupae of the Hemiptera take as much nourish- 

 ment as the larva3. 



The majority of these insects are found in their various 

 states upon plants, the juices of which serve for their 

 nourishment : some few, however, inhabit the water (as the 

 Nepidm and Notonectidfe), whilst others reside upon its 

 surface, as Gerris, Hydrometra, &c. These appear to 

 prey upon other dead or floating insects : others fly in the 

 air with great agility, although they Avalk but slowly ; and 

 some leap to a great distance, as in the Cercopidce. A few 

 of the species, one only of which is found in our climate, 

 attack man, namely, the Cimex lectularius. The majority 

 are varied in their colours ; a few only (as the Nepa grandis 

 and large exotic Cicadce) attain a large size ; the majority 

 being less than an inch in length. 



As above characterized, the order Hemiptera is divisible 

 into two sub-orders, or primary classes, the Heteroptera and 

 Homoptera, the first having the wing-covers horizontal and 



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