Eyes of FiJm.-^New Piiblualioits. j^-jg 



The mufcles of the eye, that correfpond to the ftraight raufclesin the quadruped, are four 

 in number: they are however differently placed ; they do not furround the eye-ball, but 

 two of them are on that fide of the orbit next to the nofe of the fifli, the other two on the 

 oppofite fide ; their attachment to the eye is clofe to the edge of the cornea; they do not 

 pafs round the eye-ball towards the pofterior part, as in other animals, but are con- 

 nefted with the bones of the head at fome diitance from the eye on each fide, fo that they 

 cannot at all comprefs the eye laterally; they can only pull it backward by the combined 

 effe<S of their aftions. 



The bottom of the orbit on which the eye-ball reds is folid and adapted to it, there being 

 no fat interpofed between them as in other animals ; and where the eye is removed to a 

 great diftance from the (kuU, and that cannot be the cafe, there is a ftrong cartilage pro- 

 jefting from the fkuU to the bottom of the eye, and that end of it next to the eye is con- 

 cave, and fitted to the portion of the eye-ball dire£lly oppofite the cornea, juft above the 

 entrance of the optic nerve. This is confidcred as a fixed point upon which the eye 

 moves; but it will alfo, from the fituation of the mufcles, allow the eye to be forced back 

 upon it, and the whole eye to be flattened. 



The fliape of the eye differs confiderably in different fidies ; but in all of them the tranf- 

 verfe diameter is the longeft. In the haddock the proportion is i^ths to ^'sths of an inch, 

 and in fome fifhes it differs much more. 



The fize of the eye does not correfpond with that of the fifh ; the falmon's eye being 

 fmaller than the haddock's. 



The fclerotic coat is in fome fiflies membranous*, in fome partly bonef, in others en- 

 tirely fo|; but in general the pofterior pan is membranous, although the lateral parts are- 

 bone §. 



The cornea is in general flat, not always circular in its fhape, is very thin, made up of la- 

 minx, and does not lofe its tranfparency in fpirits, appearing like talc ||. In others it is 

 more convex, as in fifli of prey ; this appears to adapt it to the fpherical cryftalline lens, 

 which in them lies direftly behind Itt- The tunica conjunftiva forms the anterior layer of 

 the cornea **, and in fome fiff.es is quite detached. 

 (The Subflonce of Mr. Home's Concluding Le^itit upon the Eye-will be given in a future 



Humber.J 



NEW PUBLICATIONS. 



Phllofophical Tranfadlions of the Royal Society of London, for the Year 1797, Part II. 

 Quarto, 541 pages, exclufive of the title, contents, lift of prefents, and index, with nine 

 plates. Sold by Elmfly, London. 



JL HIS part contains the following papers : i. On the A£tion of Nitre upon Gold- and 

 Plaiina, by Smithfon Tennant, Efq. F.R.S. 2. Experiments to determine the Force of Fired 

 Gun-powder, by Benjamin Count of Rumford, F. R. S. M. R. I. A. (fee Philof. Journal, 

 j. p. 4S9). 3- A third Catalogue of the comparative Brightnefs of the Stars ; with an in- 



» Haddock, f Sword-filh. } Devil- filh. § Mickard, |1 Sword- fifli. ^ Pjkc, ^* Ikddock. 



trodu£tory 



