5 
and mechanical Action of the Muscles of Fishes . 
produced an evident tendency to turn round, and the pectoral 
fins were kept constantly extended to obviate that motion. 
From a fourth fish, the pectoral and abdominal fins were 
cut off on one side, and it immediately lost the power of 
keeping the back upwards. The single fins were expanded, 
but the fish swam obliquely on its side with the remaining 
pectoral and abdominal fins downwards. 
From a fifth fish, all the fins were removed. Its back was 
kept in a vertical position, whilst at rest, by the expansion of 
the tail, but it rolled half round at every attempt to move. 
From a sixth fish, the tail was cut off close to the body. 
Its progressive motion was considerably impeded, and the 
flexions of the spine were much increased during the endea- 
vour to advance : but neither the pectoral nor abdominal fins 
seemed to be more actively employed. 
From a seventh fish, all the fins and the tail were removed. 
It remained almost without motion, floating near the surface 
of the water, with its belly upward. 
These experiments were repeated on the roach,* the 
gudgeon, -f and the minnow, J with similar results. 
The muscles of fishes differ materially in their texture 
from those of other animals : they are apparently more 
homogeneous, their fibres are not so much fasciculated, but 
run more parallel to each other, and are always comparatively 
shorter. They become corrugated at the temperature of 156° 
of Fahrenheit, when their tendinous and ligamentous attach- 
ments are dissolved, and their serous juices coagulated. 
Under those circumstances the muscles lose their transparency, 
and the lateral cohesion of their fibres is lessened. 
• Cyprinus rutilus. 
f Cyprinits goblo. 
J Cyprinits pboximts. 
