182 THE ZOOLOGIST. 



scratched on the glass, and week by week fresh water was added to supply 

 the loss by evaporation and keep the contents of the vessel up to the 

 original level. So situated the anemones, with some appropriate seaweeds, 

 flourished for over a year. Then their owner brought back another barrel 

 of water with him on returning from a visit to the seaside, treated his 

 Actiniithc with the entire sample of the English Channel, and killed them 

 all. — Arthur Stkadling (29, Woodford Road, Watford). 



Do Fishes Sleep ? — The Berlin aquarium is especially well arranged 

 or the scientific study of fish life, and lately it has settled a much-disputed 

 point. ''Do fishes Bleep?" lias often been asked, but never authoritatively 

 answered. Older investigators denied the possibility, but lately this 

 opinion has been changed in consequence of the following facts : — Generally 

 the life of a ash is more monotonous than that of animals or birds. The 

 fish devotes its time entirely to seeking nourishment. It does not regularly 

 hunt its prey, though it is known that it is much more active at some 

 times than at other times when it seems to rest quietly. This active state is 

 more frequent, as even when the fish is apparently playing at rest it is still 

 ready to seize on any passing prey ; but when tired or satiated it remains 

 quiet in a way that resembles the sleep of the beasts of prey. Generally 

 fish hunt by night as well as by day ; indeed some only commence their 

 activity with the twilight, and rest during the day, in certain places, 

 either lazily floating in the water, or hidden in the mud, their belly only 

 visible. These facts have been lately proved by Dr. Hermes and others. 

 In one division of the Berlin aquarium were about a dozen Carp, Cyprinua 

 carpio, that commence in October to act curiously. From time to time the 

 majority of the fish, occasionally all of them, would assume a crooked position, 

 and remain so for hours, or until they were disturbed. When worms or 

 other food were thrown into the water they would spring up to seize it, 

 and immediately resume their old position. These fish were often very 

 particular in choosing their resting-places. Some would examine carefully 

 with their heads the surrounding rocks and stones, then slowly turn them- 

 selves over to the right or left side, and either remain quiet or swim away 

 to seek some other place. Other fish would lie on the gravel, resting on 

 their heads and tails, in the form of a bow. One carp always stood on its 

 head with its body erect in the water— a veritable wonder of balancing 

 that showed the capabilities of its fins. It was easy to arouse most of the 

 fish by means of food or of a noise, but some of them slept so soundly that 

 it was only possible to disturb them by hitting or shaking them repeatedly. 

 The lidless, always open eye of the fish makes it difficult to distinguish its 

 sleep from its periods of ordinary rest, but this last experiment was con- 

 clusive. The suggestion that this behaviour is the result of illuess is 

 answered by stating that this habit of sleep was observed nearly every day 



