498 



THE MICROSCOPE. 



Fig. 252. Aphropliora spu 

 Cuckoo-spit. 



the saliva of the cuckoo, being found on the young shoots 

 of plants just about the time the cuckoo is heard in the 



woods. The frothy secre- 

 tion is supposed to be in- 

 tended to preserve the 

 tender body of the insect 

 from the overpowering ef- 

 fects of the sun ; it has 

 been observed to be pro- 

 duced in exact proportion 

 to the heat of the weather. 



a, The frothy substance. 6, The pupa. j t ig not fc nown exactly 



how the froth is produced ; and if by any chance it 

 becomes condensed, it drops like rain from the plants on 

 which the insect is feeding ; it is only during 

 tne larva state that it produces this froth. 

 The larva and the pupa resemble the perfect 

 insect, the difference simply is that the 



Fig. 253. Perfect , '. , Jj.it 



insect <>/ the cue- larva is wingless, and the pupa have very 

 lioo-spit. small wings ; the perfect insect, having both 



wings and wing-cases, which are occasionally employed 

 in the act of flying ; and at times these insects are seen in- 

 vast multitudes on the wing. One of the peculiarities 

 of this insect is its power of leaping, which is so great, 

 that, unassisted by its wings, it will sometimes leap a dis- 

 tance of five or six feet, or more than 250 times its 

 own length ; about equal to a leap a quarter of a mile 

 high, could a man take it. This extraordinary activity 

 appears to be principally due to the great length of the 

 thighs of the insect, and these are furnished on their 

 outer margins with a fringe of stiff hairs or strong spines, 

 which must be of use to the insect in leaping. 



The Hymenoptera are distinguished from other insects 

 with membranous wings, by the presence of an. ovipositor 

 of peculiar construction at the extremity of the abdomen 

 of the females, which serves for placing the eggs in the 

 required position ; and in the males of some (Bees, Wasps, 

 &c.) constitutes a most formidable offensive weapon. As 

 the structure of this organ, which is rarely absent, is 

 essentially the same throughout the order, the form of its 

 component parts being merely modified to suit the exigencies 



