394 Miscellanies. 



As there is no appearance of ciliary processes on the anterior edge 

 of the choroid coat and as in some fishes the spongy body surround- 

 ing the nerve very much resembles them when bruised and separa- 

 ted by the fingers, there is reason to believe that it performs a similar 

 office. One use of the ciliary processes seems to be to separate fi- 

 brine and other matters from the blood and thus to prepare it for the 

 formation of the humors. As the lens in fishes is large in proportion 

 to the size of the organ and very dense towards the center, the size 

 of the apparatus to prepare its nourishment appears also to be large 

 and if placed at the anterior edge of the choroid as in terrestrial ani- 

 mals it would be disadvantageous^ situated. 



Transverse section. 



A. Cartilage. 



B. Aqueous humor. 



C. Spongy body supposed analogous to 

 ciliary processes. 



■ 



16. Discovery of a Muscle in the Eye of Fishes. 



9 



Extract of a letter from W. C. Wallace, to the Editor, dated 386 Hudson St., New 



York, 16th June, 1834. 



Sir — I beg leave to announce to you the discovery of a muscle in the 

 eyes of fishes, solving the problem of the accommodation of their eyes 

 to distances in a more satisfactory way, than by a greater or less de- 

 gree of convexity of the cornea. The muscle is triangular, appa- 

 rently attached to a nerve at one extremity. Another extremity is 

 attached to the capsule of the lens at its axis. The third passes 

 through a loop in the iris, and is attached to the vitreous humor. 

 The lens is drawn backwards, when the portion attached to it con- 

 tracts. When the portion that passes through the loop, is called in- 

 to action, the vitreous humor is pulled forwards pushing the lens be- 

 fore it. This structure exists in the streaked bass, the sheep head, 

 the blue fish, the sea-bass and the poigee, are the only fishes, in 

 which 1 have had an opportunity of looking for it. If it be not too 

 late, please to announce this discovery, which I believe to be new. 

 I shall forward a more particular account, with drawings by an artist 

 before the publication of the October cumber. 



