196 Dr. John Davy on the 



On the 28th of November exposed a bee (Bombus hortorum), in 

 a languid state as to activity, in a room, the temperature of which 

 was 54°, to the open air of the temperature 32° ; it immediately 

 became more active, endeavouring to get from under the glass 

 which confined it, even spreading its wings and attempting flight. 

 How long it remained thus active I did not stop to watch. Left 

 over night, it was found the following morning quite torpid as if 

 dead. A register thermometer, placed beside it on the grass, in- 

 dicated 25° as the minimum. After having been brought into a 

 room, of the temperature 52°, in about half an hour it revived, 

 and, when touched, feebly moved its legs and walked. The same 

 bee, on the morning of the 30th, at a temperature of 48°, moved 

 its limbs slowly when touched. Exposed to the open air at 22°, 

 rising in the course of the day to 28°, it soon became completely 

 torpid, moving no part when touched. It revived as before, at a 

 temperature of 56°. 



A fly (Musca vumitoria), on the 8th December, was active, flying 

 about within doors, at a temperature of 52° ; it became dull and 

 averse from motion at 40°, and more so at 33°, at which tempe- 

 rature it did not move till touched, and then sluggishly ; even at 

 28° it was not torpid, and that after exposure during the night to 

 a temperature of 23°, as indicated by a register thermometer. 

 On the following day it was exposed under the same circum- 

 stances, in company with a bee (a Bombus), to the open air at 28° ; 

 the bee presently became torpid, the fly not, — moving its legs 

 languidly when touched. The bee, in this its torpid state, bore 

 a temperature of 22° : it remained motionless at 30° : for two 

 hours it did not revive at 54° : when placed on the warm hand 

 and breathed upon, it presently began to move one of its legs, 

 and shortly after another, and in less than a minute it was walking 

 on the hand ; removed from the hand, in a few seconds it became 

 motionless, showing no signs of life even when touched, and this 

 at 54° ; replaced on the hand, it again became active, but not so 

 soon as before, its hind legs first moved ; the movement was that 

 of passing the one over the other, as in the act of cleaning 

 them; next the fore legs were moved in the same manner, the 

 wings remaining motionless. Removed from the hand, a state of 

 torpor was induced in a few seconds. 



A fly (Musca stabulans), found within doors on the 13th De- 

 cember, exposed to the open air at 4-1°, became motionless, except 

 when touched, when it was tolerably active : even at 54° it ap- 

 peared to be in the same state, not torpid, moving only when 

 touched, and excited to motion by the gentlest touch. At 31° it 



