28 COLIN CLOUT'S CALENDAR. 



or indirectly connected with it form tlie main mass of 

 the brain ; and th(; indications of habit, as well as the 

 sniffing-muscles attached to the nostrils, all go to show 

 that smell is really the chief sence-endovvment of these 

 I)redatory species. On the other hand, their eyes are 

 relatively small and poorly developed, their optic nerves 

 and lobes are unimportant, and the general indications 

 (about which it is only possible here to speak negatively) 

 do not lead one to suppose that sight is a sense of much 

 practical value to the sharks and rays. There are other 

 classes of fish, however, in which '^ight seems to play a 

 far more important part, and here it is perhaps possible 

 to institute some rough comparison as to relative per- 

 fection with the case of the human eye and brain. 



The class of fish in which the eye is apparently best 

 developed is that of the teleosteans, to which belong the 

 perch, salmon, cod, sole, turbot, and generally speaking 

 almost all the best-known and edible species, including 

 the trout of Venlake. These fish are comparatively 

 late arrivals in our oceans and rivers, when we judge by 

 a geological standard ; but they have rapidly lived down 

 the great ganoids which preceded them, and have 

 reduced the shark family and the lampreys to a few 

 predatory or parasitic species. Externally and struc- 

 turally they differ in many particulars from all the other 

 classes offish, which are now represented only by a rela- 

 tively small numberof survivors ; but on the psychological 

 side they differ most conspicuously in this particular — 

 that, while the remaining ganoids, sharks, and lampreys 

 all show signs of depending mainly upon smell, their 

 modern superseders show signs of depending mainly 

 upon sight. The eye of these fishes is large and fairly 



