AGRIOLIMAX AGRESTIS. 109 



Animal food is also eagerly eaten, this species having been observed 

 to devour hop-aphides {Phorodmi humuli), may-flies, the young of Succinea 

 putris, etc., while in America Mr. J. Ford records that a number of A. 

 agrestis, enclosed in a box with several A. campestris, immediately set upon 

 and devoured their congeners — a veritable act of cannibalism. 



They will also on opportunity feast upon dead or moribund earthworms, 

 butterflies, and animals of their own or other species, nor does any kind 

 of animal or vegetable refuse come amiss, as even animal excrement pro- 

 vides them with some nourishment. 



A. agrestis is a pugnacious and very active species, and on a smooth path 

 can crawl two inches per minute, or at the rate of a mile in twenty-two 

 days ten hours ; it also slips easily through the fingers when grasped, 

 owing to the abundance of its thick milky-white slime, which exudes from 

 any part of the body that may be touched, this exudation, however, varies 

 in abundance according to the animal's necessities; when crawling over 

 moist ground the secretion of mucus is not excessive, but when travelling 

 upon a dry or absorbent surface, when surprised by the sun's rays, or as a 

 defence against enemies, the mucus is more plentifully secreted, and this 

 demand under certain circumstances may be so great as to totally exhaust 

 the vitality of the animal, numbers being sometimes found dried up upon 

 the whitewashed or plastered walls of country houses, where they have 

 happened to be surprised by the sun's rays when crawling over the exposed 

 absorbent walls. 



The plenitude of this viscous secretion renders this species a good 

 spinner of the mucous filaments, by means of which descent can be made 

 from elevated positions. It does not appear to be sufficiently recognized 

 that the phenomenon of thread-spinning is not due to a special secretion 

 for this particular purpose, but is merely the slime which would be exuded 

 in the ordinary way for the purpose of locomotion, and is consequently only 

 the usual slime track freed from contact with the ground or neighbouring 

 objects. 



During descent by means of this mucus-thread, which A. agrestis has 

 been observed to produce at a rate varying up to five inches per minute, 

 the locomotory area of the sole is in active undulatory movement, exactly 

 as in crawling, and the suspended animal revolves more or less quickly. 

 It is one of the readiest spinners amongst our native species, and can 

 descend from considerable heights, and if necessary is able to reascend by 

 the same thread. Mr. Henry Crowther once observed a specimen near 

 Truro, in Cornwall, descending from the branch of an elm-tree twelve feet 

 from the ground, and the slug had descended seven feet of this distance 

 when discovered. 



It is the spinning Limax of Latham, but not the Limax filans of Hoy, 

 which was described as "Limax {filans) cinereus margim flavo," peculiari- 

 ties more applicable to some species of Arion. 



A. agrestis is nocturnal in habit, but like its congeners ventures forth 

 also during the day if it be damp and showery. In dry weather and during 

 the day it hides away in secluded spots, beneath _stones,_ under clods of 

 earth, in worm-holes, etc., sometimes penetrating six or eight inches into 

 the earth. 



It is a very hardy species, only retiring for protection when the tempera- 

 ture verges on the freezing point, promptly reappearing at the advent of 

 milder weather, and being active through the winter, except during the 

 actual prevalence of frost 



