ICHTHYOLOGY. 5 



merged in water cannot extract air enough from it ; a fish 

 submerged iu distilled water, which is water minus air, 

 can get none at all, and the result is the same in both 

 cases ; and as most anglers know, or should know, a fish 

 drawn down stream is simply drowned because the water 

 is thus prevented entering its mouth in the usual way and 

 escaping through the gill-covers. For the same reason 

 fish making their way down stream for any distance travel, 

 for the most part, tail first, at least so I have heard and 

 read. An angler, therefore, when in combat with a big fish 

 need not fear being laughed at as being 



" Like those sages that would drown a fish." 

 The " migratory" fish of India, i.e. fish which travel over- 

 land from tanks and rivers, when drying up, in search of 

 more suitable lodgings, illustrate the fact that fish to a 

 great extent live by air. These fish will remain out of 

 water some days, the little sponge-like structure in each 

 cheek holding enough moisture to enable them to exist for 

 this time out of their natural element ; and we know that 

 fish kept in wet moss will live for a very considerable 

 period. How wonderfully are the Gills (brancMce) of fish 

 constructed ! They are formed of numerous arches, bor- 

 dered by a kind of fringe, which, when examined through 

 a microscope, is seen to be covered by a velvet-like mem- 

 brane, over which myriads of minute blood-vessels are 

 spread, finer than the most delicate network. Over these 

 the current of water equally flows, and the air is taken up 

 by the blood, which is sent to the gills from the heart, 

 distributed throughout the body, by means of arteries, 

 and returned by the veins to the heart again. Thus, in an- 

 swer to the 3rd Fisherman in Pericles, who said, " Master, 

 I marvel how the fishes live in the sea," the 1st Fisherman 



