Magazine edition featuring the following items - a report from State University of New York at Buffalo on the structure of birds' eggs and how their porosity enables the growing chick to breathe inside the egg; film shows how oxygen enters the egg through the multitude of small holes and how this differs in small eggs and large; also, research into the incubating behaviour of herons and terns and how this affects the development of their eggs and chicks. Newfound land Oil. A look at the social and ecological changes occurring in some of the fishing villages of Newfoundland where oil exploration surveys are being conducted.