31 
The larva of EH. tenar is the well-known rat-tailed larva 
(ver & queue de rat, so called for the first time by Réaumur IV, 
p. 443); it is figured in the same volume, plate XXX. A long 
tail, with a telescopic arrangement for prolonging or shortening 
it, enables the larvae to live several inches deep in the water 
and to pump air from the surface. They frequent putrid waters, 
sewers etc. and crawl out of them to change into pupae in the 
vicinity. The vitality of these larvae is said to be extraordi- 
nary, and for this reason Linné gave it the name tena: ,Habitat 
in fimetis, cloacis, aquis putrescentibus vix prelo (1) destruenda 
larva* (Linné, Syst. Nat. XI[th edit. p. 984, 1766). Kirby and 
Spence (vol. IV, p. 189) say: ,an inhabitant of muddy pools, it 
has occasionally been taken up with the water used in paper- 
making, and, strange to say, according to Linné (Fauna Suecica) 
resisted without injury the immense pressure given to the sur- 
rounding pulp; like Jeather-coat Jack, mentioned by Mr. Bell 
(Anatomy of Expression in Painting, 170), who, from a similar 
force of muscle, could suffer carriages to drive over him, with- 
out receiving any injury.“ Geoffroy (vol. Il, p. 521, 1762) repeats 
the same story: ,This larva also occurs in the pulp of rags 
from which paper is made; when this pulp is beaten for. the 
manufacture of paper, the larva although badly struck by the 
hammers, is not crushed, but survives and produces a fly. This 
fact would seem incredible, if it was not affirmed by the great 
Naturalist.“ (2) 
This tenacity may have been the cause of the success of 
this fly in the so-called struggle for existence. It has attained 
an almost universal distribution, and the progress of civili- 
zation has only increased its opportunities. In ancient times 
it had to look out for stray carcases. Civilization offers it its 
(1) (Translation.) ,,Lives in dungheaps, cesspools, putrescent waters; a 
roller even will not kill it.“ 
(2) In H. O. Lenz’s: Gemeinniitzige Naturgeschichte. Gotha, 1836, Vol. IJ, 
p. 490, (by the way, an excellent old book, full of original observations) the 
author calls in doubt these stories about J, tenax, and probably with good 
reason, 
