73 
1907-8.] The Body-Temperature of Fishes, etc. 
Difference between Temperature of Fish and of Water at Sea-bottom. 
Rectum. 
Blood. 
Muscle. 
f 0°6 C. 
in 
6 
specimens 
0'6 C. in 
1 specimen 
0°7 C. in 
1 specimen 
0-5 
55 
18 
55 
0*5 „ 
7 specimens 
0-5 „ 
6 specimens 
Cod 0‘4 
55 
34 
55 
0-4 „ 
10 
0-4 „ 
6 
03 
55 
20 
55 
0-3 „ 
3 
0-3 „ 
1 specimen 
1 0*2 
55 
5 
55 
Mean, 0*40 
55 
83 
55 
0*43 „ 
21 
0*46 „ 
14 specimens 
t- (0*6 
|o-4 
55 
55 
2 
1 
55 
55 
• 0-6 „ 
2 
Mean, 0*53 
55 
3 
55 
Torsk 0*4 
)) 
1 
j) 
Saithe 0*7 
55 
1 
55 
In fourteen cod, the rectal, blood, and muscle temperatures were all 
recorded in the same individual, and the mean difference between these 
figures and the temperature of the water at the time was, for the rectum, 
0 o- 36 C. ; for the blood, 0 o, 41 C. ; and for the muscle, 0 o, 46 C. 
When the body-temperature of the fish is compared with that of the 
water in which they swim near the sea-bottom, it is found that in every 
case the former exceeds the latter, but only by a few tenths of a degree. 
The conditions were as favourable as could be imagined for generating heat 
in the fish, since, for the space of two minutes immediately before the 
temperature was observed, they were using their powerful muscles to the 
utmost in struggling to get free. On most occasions the water became 
slightly warmer as the surface was approached, but the change was so 
little that it may be neglected ; and even if there had been a difference of 
several degrees, the fish were drawn up so quickly that any interchange of 
heat between their bodies and the water would have been inappreciable. 
For the same reason no heat could have been acquired from the air, which 
was never more than 3° C. above the temperature of the water, in the 
short time that the thermometer was being applied. It was not practicable 
to have the fish weighed while alive, but my impression is that the higher 
figures were obtained from the larger specimens. 
On September 26, I had a “ long-line ” set in Hoxa Sound, a strait 
about two miles wide between the islands of Flotta and South Ronaldshay, 
in the Orkney group, and connecting the Pentland Firth with Scapa Flow. 
The depth of water was from 20 to 23 fathoms, and the sea-bottom was 
clean (sand or gravel), which permitted of this method of fishing. 
