45 
LECTURE VIIL 
- - : 
Amphibia ; imagining them to be possessed of a 
kind of real lungs as well as of gills. 
The more accurate researches of modern natu- 
ralists have proved the mistake, and sufficiently 
explained its causes, and such Fishes are again 
remanded to their proper situation. 
' The generality of Fishes are covered with 
scales, of very various form and size in the differ- 
ent tribes, and even many fishes \Vhich are popu- 
larly supposed to be perfectly destitute of scales, 
“are found, on an accurate inspection, to be fur- 
nished with them, as the common Eel, for ex- 
ample. The scales in Fishes are to be considdred 
as analogous to the hair, or spines, or scales in the 
different kinds of quadrupeds, as well as to the 
feathers of birds, the animal matter of which 
they consist being nearly the same in all. 
The chief instruments of motion in Fishes are 
the fins, which may be considered as analogous to 
the limbs in quadrupeds : they consist of a certain 
number of elastic "rays or processes, either of one 
single piece, in the form of a spine^ or of jointed 
and subdivided pieces, ramifying towards the ex- 
tremity : the strong or spiny rays are usuall}'^ 
placed at the fore-part of the fin, and the soft or 
