A few experiments on feeding birds with South African butterflies are recorded by Marshall. A young Kestrel (_Cerchneis naumanni_) was fed from time to time with various species of butterflies. In most cases the butterflies offered were eaten even when they were species of _Acraea_. On the other hand _Danais chrysippus_ was generally rejected after being partly {118} devoured. When first offered this unpalatable species was taken readily and it was only after it had been tasted that the bird rejected it. When offered on several subsequent occasions it was partly eaten each time, and the behaviour of the Kestrel did not suggest that it associated a disagreeable flavour even with this conspicuous pattern. Another young Kestrel (_Cerchneis rupicoloides_) was also used for experiment. At first it would not take butterflies and at no time did it shew any fondness for them. Indeed it is doubtful from the way in which they seem to have shaped at the insects whether either of these Kestrels had had any experience of butterflies before the experiments began. A Ground Hornbill with which Marshall also experimented ate various species, including _Acraea_, but, after crushing it, refused the only _Danais chrysippus_ offered. It is hardly likely that this large omnivorous bird operates as a selecting agent in cases of mimicry. In an interesting paper published recently McAtee[74] discusses the value of feeding experiments with animals in captivity as a means of indicating their preference for different articles of diet. After reviewing the various evidence brought forward he concludes that the food accepted or rejected by captive animals is very little guide to its preferences under natural conditions. He points out that a bird in captivity not infrequently rejects what is known to form a main staple of its diet in nature, and that conversely it may eagerly accept something which, in the wild state, it {119} would have no opportunity of obtaining. Great caution must, therefore, be exercised in the interpretation of feeding experiments made with birds in captivity.