ICHTHYOLOGY. 15 



worms, which are sometimes used by anglers that employ 

 ground-baits." Possibly the organ of taste in fish, if 

 taste they have, does not reside in the mouth. However, 

 that they have some considerable faculties of taste or 

 smell, or of both combined, is pretty evident from the 

 fact that they are attracted by chemically flavoured 

 pastes and oils. Our forefathers, anglers and naturalists, 

 doubtless talked a great deal of nonsense on this point, 

 but the main fact cannot be denied. Trout are attracted 

 long distances by salmon roe prepared in a certain manner. 

 The fact that trout and perch will sometimes take an arti- 

 ficial worm made, say, of india-rubber, may be used as an 

 argument on both sides of this question ; for, on the one 

 hand, it may be argued that they have little taste or 

 smell to take such a thing into their mouths, while on the 

 other, the fact may be adduced that they immediately eject, 

 or try to eject, the treacherous bait thus taken. 



Do Fish Sleep ? — It may be presumed to start with, 

 that they do ; otherwise they would form an exception to 

 all other Vertebrate animals. I need hardly say that the 

 fact of their having no eyelids to close would be no bar 

 even to profound sleep. Many human beings sleep with 

 one eye or both eyes open, or partially so — notably infants ; 

 and hares are credited with sleeping with both eyes wide 

 open, though I cannot vouch for the truth of the asser- 

 tion. We may conclude, perhaps, that fish, if they require 

 sleep at all, do not require so much as land animals, which 

 are greater consumers of oxygen, and at the same time 

 have less nerve and muscle in proportion than fish. The 

 physiological cause of, and necessity for, sleep in land 

 animals is the enfeebling of the heart and lungs by volun- 

 tary action. A suspension of voluntary action brings 



