Dr. L. C. Birch is internationally known for his research in Population Ecology and Physiological Ecology of Animals, especially insects, and more recently he has worked on ecological aspects of Population Genetics. In these fields he has published, or has approaching publication, about forty papers, and one or two others of a philosophical character. With H.G. Andrewartha, he is the author of a book, ''The Distribution and Abundance of Animals"", University of Chicago Press, pp.782, 1954; Dr. Birch wrote about half the book. Besides his Readership in Zoology at the University of Sydney, Dr. Birch has held the following temporary positions: Research Fellowships and Scholarships at the Universities of Oxford, Chicago and Columbia, and has been a visiting Professor at the Universities of Sao Paulo (Brazil) and Minnesota.