12 
FISHES. 
Roach have only a few strong teeth in the throat, 
and a single flat one above ; and the Sturgeon, 
the Pipe-flsh, and the Sandlance, are entirely 
toothless. 
The blood, as already observed, commonly 
takes the temperature of the surrounding ele- 
ment ; in some of the swift oceanic Fishes of 
the Mackerel family, however, such as the Tunny 
and the Bonito, the blood is found to be 10° 
higher than the temperature of the surface of 
the sea, even within the tropics : the flesh of 
these Fishes is dark and dense. The blood-disks 
are sometimes circular, sometimes oval; they are 
larger than those of Mammalia and Birds ; smaller 
than those of Reptiles, and especially than those 
of Amphibia. 
The brain is small, and is divided into a suc- 
cession of lobes or ganglionic masses, ^^most of 
them exclusively appropriated to the function of 
a nerve of special sense.” The senses are pos« 
sessed probably in very different degrees. Touch 
is considered to be feebly exercised ; but the 
thick and fleshy lips of the Wrasses, the whip- 
like filaments of the Anglers, the beards of the 
Cod and Barbel, and the long flexible fingers 
in the pectoral fins of the Gurnards may be the 
seats of special sensations of feeling. Taste is 
even still more dubious. The bony character of 
the mouth, and the manner in which the tongue 
is often covered with teeth, combine with the 
circumstance that the food is almost invariably 
swallowed whole the instant it is seized, — to for- 
bid the supposition of acute taste. 
The sense of smell is probably possessed in 
considerable perfection by Fishes. The olfactory 
