PERIODICAL BIRDS TO BECOME TORPID. 111 
cotton, cn being exposed to a cold atmosphere, the 
two Dormice in the cage invariably placed them- 
selves in their usual posture of repose, when sleep 
ensued, which gradually lapsed into torpidity, ac- 
companied with all the customary symptoms, such 
as decreasing circulation, respiration, temperature, 
and irritability. While in a state of transition, the 
respiration became intermittent, and, with the circu- 
lation, ultimately ceased to be apparent. The tem- 
perature of the skin slowly descended to that of the 
atmosphere or nearly so, and the nervous irritability 
diminished so greatly that loud and sudden sounds, 
whether grave or acute, produced no sensible effect ; 
punctures also with sharp instruments, and_ slight 
electric shocks and sparks given by means of a 
Leyden-jar and an electrophorus, merely occasioned 
a degree of muscular contraction so small as scarcely 
to be discerned; but the repeated application of 
external stimuli causing bodily pain, exposure to a 
current of hot or cold air, or to a high degree of 
temperature alone, at all times prevented the animals 
from becoming torpid, and when torpid speedily re- 
vived them. 
The Hedgehog (Zrinaceus europeus), Long-eared 
Bat (Plecotus auritus), Wasp (Vespa vulgaris), Flesh- 
fly (Musca vomitoria), Housefly (Musca domestica), 
Peacock Butterfly (Vanessa io), and Tortoise-shell 
Butterfly (Vanessa urtice), when found in winter in 
a torpid state, I have frequently restored to animation 
