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LIFE, IN ITS INTERMEDIATE FORMS. 



shaped that the hind pair seem as if cut out of the fore 

 pair, with which they interlock by means of small hooks 

 during flight, so that both might readily be mistaken for 

 a single pair. The nervures are commonly stouter, and 

 form a wider network, and the membrane is generally less 

 delicate than in the preceding Order. 



All the forms of Insects which we have been enume- 

 rating agree in one point, viz., that their mouth is fur- 

 nished with biting jaws ; those that follow, on the other 

 hand, have the same organs, but so modified in develop- 

 ment and altered in function as to constitute a sucking, 

 pumping, or piercing apparatus. The elegant Lepidop- 

 tera, or Scale-icings, including the Butterflies, which are 

 active by day, the sonorous-winged Hawkmoths, that 

 probe tubular flowers in the twilight, and the Moths, 

 which swarm in the early hours of night, constitute the 

 next order. Their chief peculiarities have been already 

 mentioned, and we shall therefore merely mention the 

 Silkworm, the caterpillar of an Oriental moth, now natu- 

 ralised throughout the civilised world, as another example 

 of an Insect to which man is largely indebted. 



An extensive group is called Hemiptera, or Half-wings, 

 because the majority of them have the fore- wings curiously 

 varied in texture, the basal portions being of a stiff leathery 

 consistence, while the terminal part, separated from the 

 former by an abrupt line, is thin and membranous. The 

 vast tribe of Bugs comes here, all of them repulsive and 

 disgusting from their rank pungent odour, but in many 

 cases adorned with rich colours, and often bearing the 

 most bizarre forms. Here, too, are usually placed, though 

 distinguished by some entomologists, the insects which 



