The torpor continues as long as the cause which produces it, and ceases with the cold. A few degrees of heat above ten or eleven is sufficient to reanimate them, and if kept in a warm place during winter they do not become torpid, but go about and eat and sleep, from time to time, like other animals. When they feel the cold they crowd close together, and roll themselves up like balls, in order to present a smaller surface to the air, and to preserve some warmth. It is thus they are found during winter in hollow trees, and in holes of walls exposed to the south: in these they lie without motion, on moss and leaves, and when taken, if tossed or rolled about they never stir, or shew any signs of life; it is by a mild and gradual heat alone they are to be recovered, for if carried suddenly near a fire they perish. Though in this state they are without motion, though their eyes are shut, and they seem to be deprived of all their senses, yet they feel pain when it is very acute; they testify it when burned or wounded by a contraction, and a little hollow cry, which they will repeat several times; hence it is plain the internal sensibility must subsist, as well as the action of the heart and lungs, yet it is to be presumed that these vital motions act not with the same force and power while in the torpid as in the usual state. The circulation, probably, is not performed then but in the larger vessels; the respiration is slow and feeble, the secretions are very scanty, and perspiration must be nearly annihilated, since they could not pass several months without eating were they to lose as much of their substance in proportion by perspiration as they do when they have an opportunity of repairing it by taking of sustenance; they do lose some part, however, since in very long winters they die in their holes. Perhaps indeed it is not the duration but the severity of the cold that cuts them off, as they soon die if exposed to an intense frost. What induces me to believe that it is not from waste of substance they perish in long winters, is their being very fat in autumn, and equally so on their reviving in spring; this abundance of fat being an internal substance, sufficient to supply what they lose by perspiration. Besides, as cold is the sole cause of their torpor, and they never fall into that state but when the temperature of the air is beyond the tenth or eleventh degree, they often revive during the winter, for in that season there are frequently hours, and even days, in which the liquor will be found at the twelfth, thirteenth, or fourteenth degree, and during this mild weather the dormice quit their holes in search of food, or rather eat what they had amassed the preceding autumn.