in the Eye of' the Sepia Loligo. 199 



which it expects to discover its prey. I am inclined to adopt 

 this opinion from the following considerations: 1st, The living 

 specimen on which I had an opportunity of- experimenting 

 did not show any signs of fear when the hand or a sharp in- 

 strument was made to approach the eye, but if touched, the 

 pupil closed entirely, the skin forming the eye-lids did the 

 same, the animal became extremely agitated, and made strong 

 efforts to escape. Now, it is difficult, if not impossible, to ex- 

 plain these facts otherwise than by supposing a want of dis- 

 tinct perception in the eye of the cuttle-fish. There is one 

 objection, however, to this experiment, which candour obliges 

 me to state. It is this ; that, as the animal was placed in a 

 very small quantity of water, it was in consequence exposed, 

 perhaps, to a dazzling strength of light, which nearly closed 

 the pupil, and might have rendered the eye generally unfit for 

 distinct perception. It is, however, to be remembered, that 

 the Buccinum and Snail, animals belonging to the same class 

 as the Sepia, exhibit nearly the same phenomena as to vision, 

 and the objection does not apply to them. 



2d, We must consider the Sepia as being merely the most 

 perfect of the mollusca. Now there is no proof whatever that 

 any of these animals have distinct vision, and we know that 

 the eye of the buccinum and snail may, in some measure, be 

 considered as a miniature and less perfect representation of the 

 eye of the Sepia. Now, it is undoubtedly a general truth, 

 though it admit not of minute or particular application, that 

 animals have been formed agreeable to certain general laws, 

 and that they have been grouped into classes, the individuals 

 constituting which possess functions having a general resem- 

 blance, however much their organs may differ in appearance. 

 Thus it is with the eye of the cuttle-fish, which, notwith- 

 standing its dimensions, the beauty and complexity of its form, 

 expanded retina, and singularly constructed lens, I must still 

 consider as merely the eye of a cephalopodous molluscous 

 animal in its most perfect state. 



3d, There is interposed betwixl the vitreous humour and 

 retina an excessively dark pigment of considerable consistence, 

 assuming the form of a membrane, and apparently presenting 

 an insurmountable barrier to the passage of the rays of lighl 



