3 6 HEMIPTERA. 



The suppositions of these authors seem well founded; we have examined many 

 species that were unknown to them, and find the spine before mentioned so placed 

 in many insects as to prevent the motion of the lamellae. We have a specimen from 

 America, which, in addition to the usual organs of sound, have two large hollow pro- 

 tuberances or drums ; one on each side of the abdomen ; and must, we imagine, produce 

 a louder sound than any yet discovered ; a species very similar to this is also brought 

 from New Holland. 



The proboscis of these insects is a hard or horny tube, in which a very acute slender 

 sucking-pipe is concealed. The horny tube is not unlike a gimlet in form, and is used 

 by those creatures to bore through the bark of trees, to extract the juices on which it 

 feeds. Linnaeus has named the species of one division, in his System, Mannifera, because 

 they had been observed to fly among ash trees, bore many holes in them, and when the 

 manna had oozed out return and carry it off. 



With this proboscis they bore holes in the small twigs of the extreme branches of 

 trees and deposit their eggs in them, sometimes to the amount of six or seven hundred. 

 As each cell contains no more than from twelve to twenty eggs, it does great damage to 

 the trees they frequent. Stoll says, " the common one,* which is found at Surinam in 

 the coffee plantations, greatly injures those trees ; the females depositing their eggs in 



organs of the sound ; and he was not satisfied that the slight motion of the lamellae on these parts could 

 produce the loud singing noise of the Cicada. He opened a few cicadas on the back part of the body, so that 

 the inner structure of the under side was displayed, and especially the parts connected to the curious organs 

 he had discovered under the lamellae. At last he discovered two large muscles, which at their point of union 

 formed a space almost square, and were connected with the red triangular fields he had observed on the under 

 side : as he concluded these formed a material part of the organs he wished to discover, he examined them 

 attentively, and found that, by moving them backwards and forwards, he could make a cicada sing that had 

 'been dead many months. Although the sound was not strong, it tended to prove that he had discovered the 

 instrument that produced it. — In another part he says, it is evident the sound is caused by the little skins con- 

 nected to the muscles, because when they were rubbed with a bit of paper they emitted that kind of sound. 



Roesel has discovered two little pieces of horny substance that are connected bv a sort of fibre within the 

 skins, in the body, and he supposes when this is in motion, it strikes against the before-mentioned thin skins, 

 and produces a sound, by the same means as a hollow body, or drum, when struck with a stick : and also that 

 this noise may be varied or modulated by a slight motion of the lamellae, but cannot be produced without the 

 assistance of the internal nerves and muscles connected with the organs first described. 



Authors agree that the Cicadae of hot countries emit the loudest sound. It appears from the papers of 

 Mr. Smeethman (who resided a considerable time in Africa) published by Mr. Drurv, that the sound of some 

 kinds peculiar to that part of the world is so loud as to be heard at half a mile distance : and that the singiuo- 

 of one within doors silences a whole company.— The same attentive observer says, the open parts of the country 

 are never without their music, some singing in the evening, and others onlv in the day. 



* La Cigale Vieilleuse. Cicada Tibicen, 



