162 ON TORPIDITY IN ANIMALS. 



the dictates of necessity; on the contrary, he imagines them 



to court a lethargic habit, in consequence of certain pleasing 



sensations, which are known to precede the first moments of 



sleep. 



Objections to The preceding hypothesis is commonly supposed to assign 

 the preceding .« *",•.", . »■ , , • «• i , 



hypothesis. the true causes ot torpidity; but we doctrine is liable to 



certain objections. I will state these in the first place, and 

 afterwards endeavour to substantiate them by facts, which are 

 new, or but imperfectly understood. My objections are 

 contained in the four" following propositions. 

 Objection 1st. First, Animals do not submit to torpidity upon choice, but 

 from necessity; and when cold happens to be the immediate 

 cause, they fly from it, if possible. 

 Objection 2d. Second, Certain animals apparently support a voluntary 

 suspension of their functions in summer as well as winter, 

 when food is withheld from them; this is probably intended 

 to preserve life by diminishing the action of the system. 

 Objection Cd. Third, A quadruped noted for its lethargic disposition in 

 winter may be so far strengthened by a generous diet, as 

 to retain the full use of its faculties during the time of a se- 

 vere. frost: from which we may infer, that an emaciated 

 habit of body is the predisposing cause of torpidity, in op- 

 position to the common opinion, which assigns this office to 

 corpulence. 

 Objection 4th. Fourth, The united action of hunger and a low tempera- 

 ture has produced a kind of apparent death in a human 

 being, who was restored to life by stimulating remedies, af- 

 ter laying several days without sense and motion. 

 Thefirstobj?c- The hearth cricket (gryllus domesticusj affords a proof of 

 fie^b^the 11 the tirst ob .i ection - Those who have attended to the man- 

 hearth cricket, ners of this familiar insect will know, that it passes the hot- 

 test part of summer in sunny situations, concealed in the 

 crevices of walls and heaps of rubbish. It quits its summer 

 abode about the end of August, and fixes its residence by. 

 the fireside of the kitchen or cottage, where it multiplies its 

 species, and is as merry at Christmas as other insects are in 

 the Dog-days. Thus do the comforts of a warm hearth af- 

 ford the cricket a safe refuge, not from death, but from 

 temporary torpidity; which it can support for a long time, 

 when deprived by accident of artificial warmth. I came to 



the 



