Dinosaurs may have died out because they could not control the temperature of their reproductive organs. So says Dr. Raymond B. Cowles, of the University of California. Dr. Cowles is a leading authority on animal airconditioning. This week, writing in Science magazine, he turned his probing mind to bats and their special heat-regulating problems.
Dr. Cowles believes (with most zoologists) that warm blood is a key factor in evolution. Like diesels and steam engines, animal mechanisms are more efficient at high temperatures. This is one of the chief reasons why mammals and...