Ecology of Aquatic Insects

It is generally preferable to use principles or factors as the headings in an article on ecology, but, if these can be illustrated only by examples drawn from one group, discussion of them is necessarily one-sided and incomplete. I have, therefore, decided to present the facts that I have gathered order by order. Almost every order has attracted attention of different kind from workers who would claim to be studying in the field of ecology, and whatever about each one has attracted particular attention is given emphasis here. The scope is further restricted and certain unbalance created by the editors' request for a critical analysis of current and recent literature. Almost exactly 50 per cent of the references are dated 1955 or later. Twenty-four dating from before 1950 have been included in order to make the accounts of various lines of investigation complete, but earlier work that has not been followed up in the last decade is not mentioned. Also omitted, in view of the limits on space, are groups about which books or reviews have been published recently. Most of the references are to European work, for which I apologize to American colleagues, expressing the hope that they will agree that it is difficult to write about the ecology of unfamiliar animals inhabiting country that one has never seen.