Insects and Flowers

THE more definite relationships which subsist between organism and organism, whether it be between the algal and fungal partners of the lichen complex; between the forest tree, the orchid, or the gentian and their respective mycorrhiza; or between the Plan-arian worm Convoluta Roscoffensis and the alga Carteria, all alike bring home to one the delicacy of biotic relationships and the efficiency of whatever be the modus operandi of the evolutionary process. The relation between entomophilous flowers and the insects through the agency of which their pollination is effected constitutes no less remarkable an example of mutual specialisation than those already cited. It is scarcely surprising that the subject has attracted the attention of a considerable number of investigators from the observational period rendered notable by the publications of Koelreuter (1761), Delpino (1867), Mueller (1883), Darwin (1876), Kerner (1876), and Knuth (1898), to the experimental period of modern times initiated by the extensive researches of Plateau (1877-1910), and so ably followed by Lubbock (1882), Frisch (1913-19), Knoll (1919-22), and the work of Clements and Long, which has prompted and is the basis of the present article.1