THE FISHES. 189 



Frogs, which croak a part of the night during summer, 

 become quiet after midnight, especially when the pairing 

 season is past. 



" Insects and spiders are often found in a lethargic 

 or torpid state ; and it is probable that all animals in 

 which no regular periods of sleep and waking have 

 hitherto been observed have an equivalent for sleep in 

 the state of inactivity and rest which they from time to 

 time present." 



Dr. John Davy (" The Angler and his Friend," p. 74) 

 says : " As to sleep, fish, I believe, do rest and steep their 

 senses in forgetfulness, and this probably more by night 

 than by day. I am led to this conclusion from observa- 

 tions on very young fish. These, about the darkest part of 

 the night, when confined in glasses so as to be easily seen, 

 I have noticed immovable, resting on the bottom of the 

 vessel, and quite regardless of an approaching object, not 

 stirring until they have been almost touched ; so different 

 in this respect from their manner when awake by day. 

 Perhaps their hours of rest vary in some measure accord- 

 ing to their age and wants ; probably old and large fish, 

 like the larger carnivorous beasts the lion, the tiger 

 rest by day and then sleep ; we know that night is their 

 principal feeding-time." 



The late Mr. Manley (" Notes on Fish and Fishing, p. 

 15) asks : "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 to 

 profound sleep." At p. 16 "Query: Do they swim in 

 their sleep as somnambulists walk in their sleep ? But as 

 to the fact whether they sleep or not at night, or whether 

 they take an occasional nap or siesta by day, what is the 

 evidence ? No one, as the proverb suggests, ever l caught 

 a weasel asleep ; ' and I do not know of any one who ever 

 caught a fish asleep. A friend of mine, a good angler and 

 ardent naturalist, adduces as evidence of fish sleeping the 

 fact which, he says, he has established by experiment and 

 observation viz., that for above six hours during the night 



