352 Dr Davy on Animal Heat. 



ascertain the temperature of four specimens. This was done 

 the instant they were taken out of the water, being in a boat 

 alongside the net, by introducing a thermometer with a pro- 

 jecting bulb, through a small incision, into the muscle of the 

 back, about an inch and a half, and immediately after into the 

 cavity of the abdomen. In three instances, the thermometer 

 in the back rose to 75° Fahr. ; in one to 74° ; in all, in the 

 abdomen, it rose to 73°. The Pelamides were of moderate 

 size, between two and three feet long. The air at the time 

 was 71° ; the sea at the surface 68° : but probably at the depth 

 from which the fishes were taken, it was a few degrees lower, 

 the descending current of the Bosphorus then being, where 

 coldest, at 62°. 



Supposing that the water from which they were taken was 

 62°, — and it might have been lower, as the Pelamides swim 

 in deep water, — the temperature of this fish would appear to 

 be about 12° above the medium in which it swims, and at 

 least 7° above that of the surface. 



This result seems in accordance with the inference, that all 

 fishes are not cold-blooded. In the work already referred to, 

 reasoning from the smaller size of the respiratory nerves of 

 of the Pelamys Sarda, compared with those of the Tunny, I 

 ofi^ered the conjecture that its temperature would be found 

 less than that of the Tunny, and somewhat higher than that 

 of fishes of other orders with still smaller respiratory nerves, 

 a conjecture which the observations described may be adduced 

 as confirming. 



In connection with their temperature, my attention was 

 directed to the blood of these fishes. T have been able to ex- 

 amine it only in three instances, and that partially, viz. the 

 Sword-fish, the Felamys Sarda^ and the common Tunny, 

 Considering the great difficulty there is in obtaining the sub- 

 jects for experiment under favourable circumstances for exa- 

 mination, imperfect as were my results, I am induced to offfer 

 them now. 



The Sword-fish appears to abound less in blood than the 

 Pelamides, and the Pelamides less than the common Tunny ; 

 and, accordingly, the muscles of the former two are of a much 

 lighter colour than those of the latter. 



