PRODUCTION OF HEAT IN COLD-BLOODED ANIMALS. 849 
Consecutive Periods of Tli irty Minutes. 
OOj in 
Decini i 1 1 (grammes. 
External 
Temperature. 
Remarks. 
1055 
957 
518 
815 
683 
11' -il 
ll°-0 
31°-5 
32°-5 
n°-o 
11°'0 
.Mouse shivering and active, face and ears pale. 
Mouse less active, ears pale. 
Mouse quiet, sweating, ears flushed. 
Mouse sprawled out, sweating, apparently asleep. 
Mouse wakes up, becomes very active, ears pale. 
Mouse quiet, ears pale. 
The Production of Heat ra Cold-Blooded Animals. 
One of the most characteristic phenomena of life is an exchange of material, 
an oxidation which results in the production of heat. In the lowest forms of 
life, both vegetable and animal, a certain amount of heat is produced. 
Numerous experiments have shown that this is so, although, owing to the 
cooling effect of evaporation from the surface of the body, the heat produced 
may be masked by the excessive loss ; the temperature of a frog may be 
lower than that of the air, notwithstanding that the animal is constantly 
producing heat. 
It is unnecessary to give here an account of the temperature of plants, 1 
but, in addition to the facts already stated, 2 further details must be brought 
forward concerning the production of heat in the lower animals. Hunter 3 
found that the temperature of earth-worms, slugs, and leeches might be a degree 
above that of their surroundings; a carp had a temperature of 20° -6, a viper 
one of 20°, when that of the surroundings was 18° - 6 and 14°-4 respectively. 
In bees, even in winter, the capacity for producing heat has already been 
shown to be very great. Next in point of interest is the fact, to which 
attention was first drawn by Valenciennes, 4 that pythons, when coiled 
round their eggs during incubation, maintaui a temperature even 20° 
above that of the surrounding air. The following are some of the results 
obtained by Sclater, 5 who compared the temperature of a female python with 
that of the non-incubating male, which was kept in the same compartment of 
the reptile house : — 
Dates. 
Temperature of 
Air in Den. 
Temperature of Male. 
Temperature 
of Female. 
i 
On surface, 21° - 2 
22°-8 
Feb. 12 
14 = -8 \ 
i 
Between folds, 23° *8 
27 D -5 
f 
On surface, 22° "0 
28°-9 
March 2 
15°-6 \ 
I 
Between folds, 24° - 4 
35°-6 
1 See on this subject Dutrochet, Ann. d. sc. not., Paris (Botanique) 1840, Ser. 2, tome 
xiii. pp. 5 and 65 ; Gavarret, " De la chaleur produite par les etres vivants," Paris, 1855, 
p. 516; Sachs, "Physiology of Plants," p. 404; Vines, " Physiology of Plants " ; Van 
Tiegheni, "Traite" de botanique," Paris, 1891, tome i. It is interesting to notice that an 
abnormal rise of temperature, fever iu fact, has been observed in the tissues around a 
wound in a plant. — Annals of Botany, 1897. 
- This article, p. 792. 
3 " Works," Palmers edition, London, 1837, vol. iv. p. 131 et scq. 
4 Compt. rend. Acad. d. sc, Paris, 1841, tome xiii. p. 126. 
5 Proc. Zool. Soc. London, 1862, p. 365. 
VOL. I.— 54 
