81 
1907-8.] The Body-Temperature of Fishes, etc. 
shore crab, but its muscles are far more powerful, particularly those acting’ 
upon the chelae of the great claws. Not one of the eight starfishes showed 
any excess of temperature over that of their environment, and only com- 
paratively few of the sea-urchins. 
Results compared with those of Former Observers. 
Most of the references to work on the body-temperature of fishes and 
marine invertebrates which I have been able to obtain have been got from 
Gavarret s * book, Physique Medicate, written in 1855. From this and 
a few other sources I have collected the following facts, which, for the 
sake of brevity, I shall present in tabular form : — 
Animal. 
Excess of 
Temperature over that 
of Environment. 
Observer. 
Pike 
3°88 C. 
Kraft (1750). 
Carp 
1-94 
Hunter (1782). 
55 ...... 
0-93 
Broussonnet (1785). 
55 ...... 
3-00 
Buniva. 
55 ...... 
0-86 
Despretz. 
Tench 
0-71 
55 
55 ..... 
0-50 
Becquerel. 
Eel 
0-93 
Broussonnet (1785). 
55 ...... 
o-oo 
Davy (1816). 
Shark 
1-30 
55 55 
Bonito ...... 
10-00 
55 55 
Pelamis sarda .... 
7-22 
55 
Trout 
1*10 
„ (1816). 
,, . . ■ 
0-55 
Marline (1740). 
Bleak ( Alburnus iucidus ) 
0*55 
55 55 
Flying fish 
0*20 
Davy (1816). 
Grey gurnet ..... 
0-65 
Marlins (1843). 
Crayfish ..... 
0-60 
Davy (1816). 
Crab 
o-oo 
55 55 
Starfish (Asterias rubens ) 
0-60 
Valentin (1839). 
Sea-urchin {Echinus saxatalis ) 
0-40 
55 55 
„ ( „ brevis spinalis) 
0-50 
55 55 
Many of the above figures were obtained from one observation on a 
single specimen, and in days when the thermometer was not such an 
accurate instrument as it is at the present time. Gavarret also gives 
instances to show that the temperature of fish and other poikilothermic 
animals may sometimes be actually lower than that of the surrounding 
medium. According to him, most frequently the body of the animal j* 
* Gavarret, Physique Me'dicale, Masson, Paris, 1855, pp. 125-141. 
t It is difficult to believe that the body of a fish can have a lower temperature than the 
water which surrounds it, if the temperature of the water is stationary and not slowly rising. 
VOL. XXVIII. 6 
