From the December 12, 1931, issue

SCIENCE AT THE WORLDS CROSSROADS

Everybody has heard of Barro Colorado, the hill that was turned into an island, and was set aside as a great animal sanctuary; but only a few persons have ever set foot on it. In the nature of things, an animal sanctuary cannot be opened to crowds of visitors, so the only callers are the few scientists who have to meet the birds and beasts and plants on business.