1879.] 135 



Dragon-flies and telegraph wires. — Small LibellvlcB hold a daily parade upon tlie 

 telegraph wire. I noticed them upon my way from Greneva ; and since then a French- 

 man (ignorant of Entomology) was so struck by their singular appearance that he called 

 my attention to them. When one chances to catch a fly it returns to the wire to eat 

 it (the fly, not the wire). — A. E. Eaton, Samoens, Savoy : 12th September, 1879. 



An unrecorded habit in the life-history of certain Trichopterous insects. — Mr. 

 Salviu recently placed in my hands three leaves of hazel, upon each of which 

 was a gelatinous mass, enveloping either ova or recently-hatched larvae of some 

 Ti'ichopterous insect ; the bushes upon which they were found were situated at a 

 considerable distance from the nearest stream. The ova in the still undeveloped 

 mass were arranged in regular series, made still more evident by the two black eye- 

 spots of each embryo, which shewed both through the eggs and through the viscid 

 surroundings. After the lapse of about twenty-four hours, the previously unhatched 

 larvaj were roaming in their transparent environment, and some of those already 

 hatched had left it, and were wandering about the box, probably in search of the 

 element they were not destined to find, and their size had wonderfully increased 

 since they were hatched. 



Only a few days before this experience, Mr. Eye informed me that poplar leaves 

 bearing similar gelatinous masses had come under his notice. This reminded me 

 that Prof. Westwood had once either recorded, or mentioned to me verbally, quite 

 a parallel case (I now believe it was a verbal communication) ; the accumulation of 

 evidence appears worthy of notice in a more prominent manner. 



The size of the gelatinous masses was considerable ; undoubtedly large at the 

 time of deposition, and increased by the absorption of moisture from the air. The 

 juvenile larvte appeared to me to belong to the Family LimnophilidcB, and, con- 

 sidering the time of year, I have little doubt they pertain to the genus Halesus, all 

 the conditions agreeing therewith. 



These observations open up more than one interesting problem in the early life- 

 history of Trichopterous larvse. Halesus is a genus the larvse of which frequent 

 streams. The larvse hatched from the egg-masses collected by Mr. Salvin would 

 have had to travel many yards before they reached the nearest stream, or water of 

 any kind, save that resulting from recent rains. Furthermore, it appears to me that 

 the gelatinous secretion in which the eggs are enveloped may serve as food for the 

 young larvse, otherwise it is difficult to account for the very considerable increase in 

 size of those I had under observation, amounting in less than two days to about 

 double that of tlie newly emerged larva. 



All Trichoptera (so far as is known) void their eggs iu a viscid surrounding. 

 Most of them deposit this mass in the water or on water plants. In the case now 

 under consideration it appears probable that certain of them prefer (either habitually 

 or casually) to avert immediate contact with the element in which their progeny 

 must eventually pass the greater part of their lives, and to trust to chance that some 

 of them may, at the proper time, reach their aquatic home. 



There is mystery about the infantine life .of most Trichopterous larvae, not- 

 withstanding that it was from observations on the eggs of a species of this Order 



