10-2 EXTRICATION OF THK IMAGO IN A CRANE-FLY. 



middle of October, I observed what appeared to be the body 

 of a small crane-fly, projecting from the moss ; upon examin- 

 ing it more closely, I found it was an imago disengaging itself 

 from \he pupa-case, (there was no appearance of a larva-case): 

 the head and thorax were very small, but the abdomen was 

 stretched out, and to all appearance quite rigid, being about 

 half an inch in length, and one sixteenth in diameter. The 

 wings were expanded, and spread out at right angles to the 

 body ; the apex of the abdomen was still enclosed within the 

 pupa-case ; the legs were not yet extricated from their e,Tu- 

 vice. The colour of the abdomen was whitish, but, from its 

 extreme tenuity, owing to its excessive enlargement, it was 

 perfectly transparent, showing the intestinal canal as a very 

 dark, fine thread within it. After watching it for some time, 

 andfuot observing any motion, I thought it had died, as the 

 previous night had been very cold ; but while I went into the 

 house for a knife to detach the moss from the wall, it disen- 

 gaged itself, and when I returned w^as creeping about and 

 fluttering its wings, the abdomen remaining distended as be- 

 fore. I pricked it with a fine pin, when it instantly shrunk 

 to about a line and a half in length, and the thickness of a 

 common sewing-thread ; losing its transparency, but not its 

 colour, remaining of an opake white for about half an hour, 

 when it began to assume its natural hues. On examining the 

 wall I found numberless exuvice in positions exactly similar 

 to the one above described, and afterwards observed several 

 imagoes flying about with the abdomen of the size and colour 

 mentioned, not having yet assumed its natural dimensions and 

 appearance. In one the abdomen was considerably reduced 

 in length, but not in its lateral dimensions ; the cause of so 

 unusual a condition I suppose to be owing to the length of 

 the legs, which, when stretched out to their full extent, mea- 

 sured about nine lines in length. Most other insects make 

 use of their legs in extricating themselves from their exuviae ; 

 but in this, owing to their length so greatly exceeding that of 

 the body, it is evident there must be some other method of 

 extrication, which is effected by the elongation of the abdo- 

 men. There were numberless small patches of moss on the 

 wall, many of them not above a line in extent ; but I could 

 not find one which was not infested by these larvce, and I 

 often saw them, after having devoured the roots of the moss 

 where they had been hatched, creeping about in search of 

 another habitation. By the end of October they had destroyed 

 every vestige of the moss, not one living plant of it being 

 found anywhere on the wall, by the most diligent search. — 

 James Bladon. — Pontypool. — January 11///, 1840. 



