[page] V

Papers read.

Mr. Müller read a paper on the "Dispersal of Non-migratory Insects by Atmospheric Agencies," in which he had collected together many records in support of his opinion that various atmospheric phœnomena played a considerable part in the wide dispersal of insects, and explained many points connected with their present geographical distribution.

In the discussion which followed, the President said he was quite of opinion that currents of air were the chief agencies in the peopling of oceanic islands with the smaller forms of animal life; though, no doubt, floating timber had the same effect, but in a lesser degree.

Mr. Bates and Mr. Pascoe asked how it was that the Coleopterous fauna of the opposite sides of high mountains, and mountain-chains, presented such marked differences, if their insect-inhabitants were liable to be carried over the summits by atmospheric agencies? And Mr. F. Smith, Mr. Pascoe, and Mr. M'Lachlan remarked on the extreme difficulty of naturalising insects in localities which apparently present no important climatic differences from those in which the species experimented upon are abundant.

Mr. Müller, agreeing with the suggestion thrown out by several members, explained this by the hypothesis, that though many individuals are dispersed in the manner he indicated, yet, owing to causes difficult to comprehend, the strangers are unable to cope with the pre-existing denizens of the locality, and thus only very few are able to maintain their position, and most of these die out before they are able to give birth to new varieties or incipient species.