The Zoologist— February, 1874. 3879 



witness-box, and must know of a certainty whether they are 

 diurnal or nocturnal. If you find that fishes of any particular 

 genus, — Labrus, for instance, — are incessantly in action during the 

 day, always roving about seeking food or pleasure, perhaps striving 

 to display their splendid colouring, or perhaps siraply desiring to 

 convince wondering visitors that they have discovered perpetual 

 motion, — be this as it may, you may pretty safely conclude that 

 these beautifully decorated wrasses are not to be caught napping 

 while the sun is above the horizon. Visit them in the dead of 

 night and with a lantern, and you will find that a change has 

 come o'er the scene ; the perpetual motion, as in so many other 

 instances, has come to a dead stand ; the machinery is out of order 

 and has ceased to work : the wrasses are scattered about in a variety 

 of attitudes and are perfectly motionless; some are on their sides, 

 some seem to be jammed in the crevices of a rock, some seem to 

 be standing on their noses, and some on their tails : none make 

 any attempt at motion, unless when the light of the lantern is 

 brought to bear on them too brightly or too suddenly. We may 

 fairly conclude when they exhibit these appearances that they are 

 asleep,— that they are really taking rest in sleep, — and thus the 

 question would be solved as regards wrasse. 



But look on those algophagous gray mullet; they swim about in 

 mid-water by day soberly and sedately, too aristocratic to take 

 notice; too confident of safety either to hurry or to hide ; they seem 

 to be enjoying a waking dream, but there is no evidence that they 

 are asleep. At night how different the scene ; then they are all on 

 the surface, and all in a state of the greatest activity, most of them 

 have the dorsal fin actually out of water: these are truly nocturnal 

 fishes ; it is impossible to catch them asleep by night, and we have 

 no evidence that they sleep by day : therefore they do nothing 

 towards solving the question. Do fishes sleep ? 



It may be observed that the absence of an eyelid and the con- 

 sequent absence of the power to close the eye, are facts which 

 have evidently induced the erroneous conclusion that fishes cannot 



^ ^^P' Edward Newman. 



Curious Instinct in the Mole. — Beiug much annoyed by moles, I set a 

 trap in a large warren, which was at first successful. Having, however, 

 reset the trap, I was surprised, two days after, to find that the mole on 

 coming to the trap had made a hole to the surface, and then, passing over 



