278 
PHYSIOLOGY. 
BOOK ir. 
The 14th, at 3 p.m. 4° 5 centigrade 
15th, 4 p.m. 10° 
16th, 5 P.M. 10° 2 
17th, 5 P.M. 11^ 
18th, 11 A.M. 8° 2 
19th, 10 A.M. 2° 5 
These maxima might be almost compared to the access of 
an intermittent fever. 
That these phenomena should not be observed in ordinary 
cases, is no proof that they do not also occur; for it is easy to 
comprehend that, when flowers are freely exposed to the ex- 
ternal air, the small amount of caloric which any one may 
give off will be instantly dispersed in the surrounding air 
before the most delicate instrument can be sensible of it ; and 
that it is in those cases only of large quantities of flowers col- 
lected within a hollow case, like a spathe, which prevents the 
heat escaping when evolved, that we can hope to measure it. 
From experiments of Saussure, it seems certain that the dis- 
engagement of heat, and, consequently, destruction of oxygen, 
is chiefly caused by the action of the anthers, or at least of 
the organs of fecundation, as appears from the following 
table : — 
Names. 
Duration 
of the 
Experiment. 
Oxygen destroyed. 
By the bud. 
By the 
flower dur- 
ing its ex- 
pansion. 
By the 
flower in 
withering. 
Passiflora serratifolia 
12 hours. 
6 times its vol. 
12 
7 
Hibiscus speciosus 
24 
6 
8,7 
7 
Cucurbita maxima, 
male flower - 
24 
7,4 
12 
10 
Arum italicum,spadix 
cold - - - 
24 
5 to 6 
30 
24 hours after 
5 
It was also found that flowers in which the stamens, disk, 
pistil, and receptacle only were left, consumed more oxygen 
than those that had floral envelopes, as is shown by the fol- 
lowing table : — 
