Hereditary Choice of Food Plants in the Lepidoptera and its Evolutionary Significance

Abstract

MR. EDWARD MEYRICK, in his comments (NATURE, Mar. 12) upon my paper (Proc. Roy. Soc., B, vol. 101, pp. 115–127) on the egg-laying instincts of Pontania salicis, so completely misses the point that it is difficult to deal with them seriously. The “new principle” to which he refers does not depend in the slightest upon the work he mentions, but is deduced from work described in an earlier paper (Proc. Roy. Soc., B, vol. 99). It may be summed up in two sentences: (1) Chemical agencies acting through ingested food have been shown to act directly on the germ plasm so as to affect its potentialities; (2) Therefore any circumstance bringing about a change in the food ingested by an organism may affect its germ plasm so as to produce heritable variations.