6 LIMACID^. 



boiling water. They leave a trace of tlioir usual secre- 

 tion on every object over which they pass, and thus can 

 easily be tracked to their retreats. The ordinary secre- 

 tion is most abundant at their jiosterior extremity. The 

 secretion of the mucous fluid over their surface is neces- 

 sary to tlu'ir existence. Death immediately follows the 

 failure of this power, and is jirecedod by the drying up 

 of the skin. 



All the species are extremely voracious, and devour 

 an incredible quantity of food in a short time. Those 

 found in this country are generally supposed to be vege- 

 table feeders, but nearly all of them subsist occasionally 

 upon dead animal matter of which they seem to be fond, 

 and when in confinement sometimes attack and devour 

 each other ; and the foreign genus, Tcntacella, is known 

 to prey habitually upon cai'th-worms. It is probable, 

 therefore, that in their natural condition, all of them at 

 times resort to animal food, and devour earth-worms, 

 insects and their larvre, and such other animals as, 

 inlmbiting the same retreats, are like themselves slow of 

 motion and defenceless. It is certain, however, that the 

 principal food of those species which frequent the neigh- 

 borhood of houses and gardens, consists of the tender 

 leaves of suceident plants and of ripe fruits. Upon 

 these, in Europe, they perpetrate serious ravages, 

 often destroying in a night the labors and hopes of the 

 gardener, and in some years committing so nnieh in- 

 jury, and interfering to such a degree with the prosperity 

 of the agriculturist that they arc ranked among the 



