Page:The Book of the Aquarium and Water Cabinet.djvu/58

48, Paludina vivipara, Lymnea stagnalis, putris, auriculata, and glutinosa, Physa fontinalis, Bythinia tentacula.

Bivalves.&mdash;Anodon cygneus, Unio pictorum, tumidus and margaritiferous, Dressinia polymorpha, Cyclas corneus.

should be performed twice or thrice a week, and will be as amusing to the observer as gratifying to the fishes. Bread is not so objectionable as many have stated. Carp, bleak, and minnows eat it greedily, and soon grow tame if regularly fed with it. Most small fishes take insects, such as flies, spiders, ants, and soft larva, greedily; but the large fish disdain such diet. Small red worms, and white of egg, are good general foods, and seem highly beneficial. When feeding, see that the carp get enough, for they are slow fish, and get robbed wholesale by their more lively neighbours. Food not eaten will decay, unless speedily removed, hence care must be exercised on this head.

Confervæ.—When the tank has been established a few weeks, the inner sides of the glass will show signs of a green tinge, of a slimy nature. This is owing to the growth upon it of minute forms of vegetation. If this is allowed to go on unchecked, the glass will in time become opaque, and the view of the interior will be lost. Hence it must either be kept down in growth or occasionally removed.

Uses of Mollusks.—It is to prevent this rapid growth that water-snails are registered among the tenants of