the importance of co-operative research for the British Empire rests upon the twin foundations of the potential wealth of the Empire countries and their sparse population, which is reflected both in the numbers of their scientists and in the limited inducements they can offer to first class research men. The last difficulty is of particular importance to Canada where the neighbouring territory of the United States offers a more completely industrialized area, with better opportunities for, and larger rewards to, scientific men and to whom, therefore, the Dominion loses a considerable proportion of its most promising young research workers.