371 
striking to be liable to any exception. In addition 
to the observations of M. Hubert on the heat of the 
arum cordifolium, we may now state others, made on 
another species of the same genus, by M, M. La- 
marck and Senebier. M. Lamarck observed the 
flower of this plant, at the period of fecundation, to 
communicate the sensation of heat, and a similar ob- 
servation was made by M. Senebier. The maximum 
of heat occurred about six hours after mid-day, when 
it exceeded that of the atmosphere by nearly 12 
Fahren. During the development of this heat, the 
flower in part became black ; and the rapid combina- 
tion of oxygen with the carbon of the flower may, 
says M. Senebier, be suspected as the cause of this 
appearance : but he did not, by experiment, ascertain 
the fact *. The more accurate observations of M. Hu- 
bert (171.), have shewn that this great increase of 
heat is accomplished chiefly by the external surface 
of the spadix of the flower ; that the presence of air 
is necessary to its production ; and that, during its 
development, the pure part of the air is consumed ; 
whence it may be inferred that this heat is immedi- 
ately derived, from the extrication of caloric by the 
consumption of oxygen gas* 
684. We have already given examples (173. et 
seq.), which prove that worms, insects, fishes and 
reptiles, possess, in many instances, a temperature 
higher than that of the medium in which they live ; 
and we have also maintained, that, as this small excess 
of heat is constantly passing off to the surrounding 
* Phvsiol. Veg. torn. iii. p, 314. 3J~ 
