112 ON THE SUPPOSED CAPABILITY OF THE 
by subjecting them to a high temperature, perfect 
torpidity having been again induced on submitting 
them to the requisite degree of cold. 
In the year 1329 I captured several specimens of 
the large aquatic Beetle Dyticus marginalis, for the 
purpose of making some observations and experi- 
ments relative to the structure and use of the 
cup-shaped suckers with which the males have 
the tarsi of the first and second pairs of legs 
provided on the underside; and putting them 
into an earthenware vessel containing water, I sup- 
plied them during several weeks with raw flesh, 
which they devoured greedily. The month of De- 
cember in the same year terminated in severe 
frost ; the maximum temperature of the last week 
was 37°, the minimum 16%5, and the mean 
28°75 ; consequently the water in the earthenware 
vessel was frozen into a solid mass of ice, and it 
remained in that state for some days; yet, on 
being gradually thawed, the Beetles resumed, and 
long continued to exercise, their customary func- 
tions. 
From the foregoing experiments and observations, 
it appears that birds are not liable to be rendered 
torpid on being exposed to the same external agency 
which quickly induces torpor in various animals 
known to possess a constitutional proneness to 
that state of lethargy. It is obvious, therefore, that 
they must differ physiologically from those animals ; 
