26 Fisninc iv American WATERs. 
Either a reward should be offered by each state for every 
porpoise killed in its waters, or gentlemen who compose 
sporting clubs for taking the game fishes of our coast and 
estuaries should adopt a plan for capturing and driving them 
away. The porpoise is one of the most profitable fishes for 
capture, as its oil is the finest possible, and used exclusively 
by watcbmakers. 
SECTION FOURTH. 
ON VISION IN FISHES. 
The brain and nerves proceeding therefrom, a, a, b, b. The lobes of the brain in five 
ranks, ¢,¢. The nerves of the eye, d,d. The nerves of smell, branching off into di- 
vergent filaments upon the nostrils, e, ¢. 
That certain senses are bestowed on all animals, intellect- 
ual as well as instinctive, is too self-evident to the man of- 
science and the angler to require proof. These animals need 
both, more than do those which dwell on land, to avoid being 
devoured, and to aid them in capturing and devouring other 
fishes; for their fortifications are often insecure, and they are 
obliged to leave them frequently, and always to commit 
slaughter, or to swallow minor species whole. 
In order, therefore, to render this work practical, it is hard- 
ly necessary that I should dwell upon principles of science 
farther than to show by the nature and habits of fishes the 
motives by which they are actuated, which appear to be, in 
the main, efforts to eat and prevent themselves from being 
eaten, These efforts, carefully studied, will assist the angler, 
and the fisher with nets and other devices. Fishes are gen- 
