PISCES. 9 



for their tongue seems not to have been designed for 

 a very nice sensation, being of a pretty firm carti- 

 laginous substance; and common experience evinces 

 that their sight is not of so much use to them as 

 their smell in searching for their nourishment. If you 

 throw a fresh worm into the water, a fish shall di- 

 stinguish it at a considerable distance ; and that this 

 is not done by the eye is plain from observing that 

 after the same worm has been a considerable time 

 in the water, and lost its smell, no fishes will come 

 near it ; but if you take out the bait, and make 

 several little incisions into it, so as to let out more 

 of the odoriferous effluvia, it shall have the same 

 effect as formerly. Now it is certain that had the 

 animals discovered this bait with their eyes, they 

 would have come equally to it in both cases. In 

 consequence of their smell being the principal means 

 they have of discovering their food, we may fre- 

 quently observe them allowing themselves to be 

 carried down with the stream, that they may ascend 

 again leisurely against the current of the water : 

 thus the odoriferous particles swimming in that 

 medium, being applied more forcibly to their organs 

 of smell, produce a stronger sensation. 



The optic nerves in Fishes are not confounded 

 with one another in their middle progress betwixt 

 their origin and the orbit, but the one passes over 

 the other without any communication ; so that the 

 nerve which comes from the left side of the brain 

 goes distinctly to the right eye, and vice versa. 

 Indeed it should seem not to be necessary for the 

 optic nerves of fishes to have the same kind of con- 



