f»54 INSECTS FIRE-FLIES. 



the hammock, and out of the window, near which it hung. 

 He said they were on their way somewhere, and if left undis- 

 turbed would be gone in an hour or so. 



INSECTS EIRE-FLIES. 



Of those diamonds of the night, the fire-flies and fire- 

 beetles, there are numerous species. One of the most abun- 

 dant- — and of much larger dimensions than the rest of the 

 elaters or beetles — pyrophorus noctilucus, called by the natives 

 cocuja, displays both red and green light On the upper sur- 

 face of the thorax there are two oval tubercles, hard and 

 transparent, like bull's-eye lights let into a ship's deck. These 

 are windows out of which shine a vivid green luminousness, 

 which appears to fill the interior of the chest. Then on the 

 under surface of the body, at the base of the abdomen, there 

 is a transverse orifice in the shelly skin, covered with a deli- 

 cate membrane, which glows with a strong ruddy light ; visible, 

 however, only when the wing-cases are expanded. It is about 

 an inch and a half long, of a brown colour, and has a strong 

 spine situated beneath the thorax, which fits at pleasure into 

 a small cavity on the upper part of the abdomen. By means 

 of this machine it can, when placed on its back, spring up a 

 couple of inches, and regain its feet. When preparing to do 

 this it moves its head and thorax backwards, so that the pec- 

 toral spine is drawn out and rests on the edge of the sheath. 

 The same backward movement being continued, the spine, by 

 the full action of the muscles, is bent like a spring, and the 

 insect at this moment rests on the extremity of its head and 

 wing cases. The effort being suddenly relaxed, the head and 

 thorax fly up, and in consequence the base of the wing-cases 

 strike the supporting surface with such force that the insect 



