212 



that of the atmosphere, but less than that of cold- 

 blooded animals. When the atmosphere was below 

 .56, the temperature of the tree was always above 

 it ; but when the weather was warm, the heat of the 

 tree was several degrees lower *. 



170. But the most remarkable and decisive facts, 

 relating to the temperature of vegetables, are con- 

 tained in the following account of M. Hubert, con- 

 cerning the heat given out by the sfiadices of the 

 arum cordifolltim during the process of fecundation. 

 This plant grows in Madagascar and the Isle of 

 France : its flowers exhale a strong and rather plea- 

 sant odour. About sun-rise, M. Hubert tied five 

 spadices, which had unfolded during the night, round 

 the bulb of a thermometer, and the mercury rose to 

 44 \ while another instrument of comparison, at 

 six o'clock in the evening, was only 19. At eight 

 next morning, the standard thermometer was only 

 21, and that used in the experiment had fallen to 

 42 ; and by nine at night had sunk to 28, while 

 the first remained at 21. The next day, at nine in 

 the morning, the thermometer of experiment follow- 

 ed the ordinary course. These trials were repeated 

 seven or eight times with similar results. When 

 surrounded with very fine spadices, the mercury rose 

 to 45, but reached only to 42 with the smallest ; 

 and, in one instance, where the thermometer was 

 surrounded by twelve flowers, the maximum of heat 

 was 49.5. The male parts of six spadices raised 

 the thermometer to 41% while the same number of 

 the female parts of the flowers raised it only to 2&* 



Encyclop, Brit. art. Physiology. 



