352 MOTIONS OF INSECTS. 



Orthoptera, in a waving line, is equally alert and active 

 after its prey. This however often alights for a mo- 

 ment, and then resumes its gay excursive flights. The 

 species of the genus Agrion cut the air with less velocity; 

 but so rapid is the motion of their wings, that they be- 

 come quite invisible. Hawking always about for prey, 

 the Agrions, from the variety of the colours of different 

 individuals, form no uninteresting object during a sum- 

 mer stroll. With respect to the mode of flight of the 

 other rieuropterous tribes I have nothing to remark ; for 

 that of the Ephemera, which has been most noticed, I 

 shall consider under another head. 



The next order of insects, the Hymenoptera, attract 

 also general attention as fliers, and from our earliest 

 years. The ferocious hornet, with its trumpet of terror; 

 the intrusive and indomitable wasp ; the booming and 

 pacific humble-bee, the frequent prey of merciless school- 

 boys ; and that universal favourite, the industrious inha- 

 bitant of the hive, all belonging to it, are familiar to 

 every one. And in summer-time there is scarcely a flower 

 or leaf in field or garden, which is not visited by some of 

 its numerous tribes. The four wings of these insects, 

 the upper pair of which are larger than the under, vary 

 much in their nervures. From the saw-flies (Serriferd), 

 whose wings are nearly as much reticulated as those 

 of some Neuroptera, to the minute Chalcis and Psilus, 

 in which these organs are without nervures, there is 

 every intermediate variety of reticulation that can be 

 imagined a . It has been observed that the nervures of 

 the wings are usually proportioned to the weight of the 

 insect. Thus the saw-flies have generally bodies thicker 

 a Jurine Hymenopt, t. 2-5. 



