The quantity required for each pond or aquarium is a matter for personal judgment. There is one consolation, however ; it is impossible to overfeed with this particular type of food. If the fishes do not eat them all they will continue to breed and there need not be any fear that they will breed to such an extent as to crowd out the fishes. As soon as a certain point is reached food supplies will be inadequate and so the daphnae will die off.

Cyclops is a smaller and differently shaped crustacean. The body is an elongated oval and the name ' cyclops ' is derived from the single red eye situated in the middle of the head region. From each side of the female may be seen the egg sacs, like a pair of pale green wings. Cyclops is an admirable food for young fishes that have passed the infusoria stage of their diet. They can be raised in the manner described for raising daphnae.

Another small crustacean is Cypris, similar in outline to daphnae ; but, whereas daphnae has a thin, transparent shell, that of cypris is hard and horny, not at all appreciated by the fishes. However, it makes an interesting aquarette inhabitant.

Gammarus pulex is another misnamed ' water-flea,' although I must admit that this Amphipod greatly resembles a highly magnified Pulex irritans. The length of Gammarus often exceeds half an inch and so it forms a fine food for the larger fishes. They are fairly common in sluggish streams and can be bred quite easily in small aquariums. An old sink, with the hole stopped up, and planted with a few plants, makes a better home for them. Lettuce leaves and an occasional piece of raw meat will satisfy this creature as regards food.

Slightly larger still are the Fresh-water Shrimps (Asellus aquatilis). They, too, are misnamed for they are not in the least like the shrimp of the fishmonger's slab. In reality they are more like the Wood Bug of the garden, to which they are closely related ; that is to say, they are both Isopods. They are interesting for the aquarette and are a splendid addition to the diet of large fishes.

Aquarettes
This brings us to the aquarette itself, which, as the name implies, is a small aquarium. Instead of housing fishes, this type of aquarium is, when properly set up with plants and so forth, the home of individual species of other aquatic life.