Transference of induced food-habit from parent to offspring—II

The first part of this investigation was published in 1934 (Sladden, 1934). When that paper was read to the Society a discussion followed in which it was pointed out by critics that little or nothing was known of the habits of the stick-insect in its native country, India. In order to meet this criticism, the communicator of the paper (Professor E. W. MacBride, F.R.S.) instituted an extensive inquiry and obtained information from Northern, Central, and Southern India, from Ceylon, and also from Siam. The replies received give some idea of the local knowledge of the habits and systematics of this insect and supply information particularly relevant to the criticisms, although little work relating to this insect appears to have been done by Indian naturalists. The ivy (Hedera helix), which was used as a food-plant in the experiments, was shown to be an inhabitant of Northern India; it clothes the middle slopes of the Himalayas; it is, in fact, a member of the Holarctic flora which descends to a level of about 2000 feet. On the southern slopes of this mountain range and at about this horizon the boundary between Holarctic and Oriental regions is drawn. A considerable number of plants (56) belonging to the ivy family (Araliaceae) are common in India, although none of them is closely allied to Hedera itself. About 20 plants of the Oleaceae, the family to which the privet (ligustrum) belongs, are also found in India. A species of privet, it will be remembered, is the food-plant employed by breeders of the insect in Europe.