Hoe een kleine Nachtpauwoog zich dik eet

An account is given of a simple experiment in which differences in size of Pavonia pavonia may possibly be explained by the kind of plant on which the larvae feed. Caterpillars were placed in a glass tank with either apple leaves or bramble leaves. Those feeding on apple grew faster and pupated earlier. Pupae of the apple-eaters were heavier than those of the bramble-eaters.