NATURAL HISTORY. 353 



" Being moody, give him line and scope ; till that his 

 passions, like a whale on ground, confound themselves with 

 working." SUAKSPKUE. 



1147. Why may a fish be "drowned" when being "played" 

 Inj an angler? 



Because fishes breathe by passing water, which always holds 

 common air in solution, through their gills, by the use of a series 

 of muscles connected with them. 



When a fish is hooked in the upper part of the mouth, it is 

 scarcely possible for him to set the muscles in action which 

 move the gills, while the rod is applied as a lever to the 

 line, so that no aerated water can be respired. 



1148. A fish, hooked in a part of the mouth where the force of the rod will render 

 his efforts to respire unavailing, is much in the same state as that of a deer caught 

 round the neck by the lasso of a South American peon, who gallops forwards 

 dragging his victim after him, which is killed hy strangulation in a very short 

 time. When fishes are hooked foul thai is, on the outside of the body, as in the 

 fins or tail they will often fight for many hours, and in such cases Tery largo 

 salmon are seldom caught, as they retain their powers of breathing unimpaired : 

 and if they do not exhaust themselves by violent muscular efforts, they may bid 

 defiance to the temper and the skill of the fisherman.* 



1149. Why is the migration of fishes of great importance 

 to mankind ? 



It is by these migrations that the blessings of fis>h diet are 

 periodically bestowed upon the inhabitants of shores remote from 

 each other. If such fishes were constant residents in any one 

 locality, we might feed on them to satiety ; but, by a temporary 

 privation, we learn to estimate the value of the treat, and to 

 hope for the periodical return. 



1150. Why do fishes generally spawn in shallow waters? 

 Because a certain degree of solar heat and light is necessary 



for quickening the eggs into life ; and also because the young fry 

 are thereby protected from large fish. 



1151. Why does the sea sometimes exhibit a luminous 

 appearance ? 



Because of the great numbers of medusce, or jelly animalculse, 

 which, being congregated in one part, under certain conditions 

 emit a phosphorescent light. 



* " Salmouia." 



