Eyes and other Objects. 67 



the outside portions of a " dissected map " are fastened 

 together. 



These lines present slight dissimilarities of appear- 

 ance in the lenses of different kinds of fish, and speci- 

 mens of a number might gradually be collected. Op- 

 ticians also supply interesting preparations preserved 

 in fluid, of the minute fibres from the eye of a cow 

 and other animals, also of the iris, and the black pig- 

 ment lining of the eye-ball. I have before me as I 

 write, a specimen labelled " Fibre of Lens of Human 

 Eye," and I naturally view it with interest, mingled 

 with reverence, because it once formed part of that 

 which has been aptly named the " window of the 

 soul/' It consists of a multitude of separate fibres, 

 broader than those of the cod-fish, and with compara- 

 tively smooth edges, exhibiting, however, sufficient 

 roughness to enable them to catch the edges of the 

 neighbouring fibres. 



These fibres, it is stated, converge in the human 

 eye to a Y-shaped figure instead of to poles, as those of 

 the cod-fish do. The fibres in a trout's lens meet at 

 straight lines, and various other forms have been ob- 

 served and noted. 



A considerable resemblance to the plan which has 

 just been imperfectly described may be traced in the 

 eyes of crustaceous animals, as the crab and lobster, 

 in those of insects, of spiders and other creatures.* 

 There may be the greatest diversity of arrangement : 

 the eye may be fixed or movable, single or immensely 



* See Dr. Spencer Thompson's interesting work on " The Struc- 

 ture and Functions of the Eye." Groombridge and Sons. 



