The 11th edition of the Encyclopedia Britannica marked the beginning of its transition from a British to American publication. It came out in several volumes between 1910 and 1911. The New York Times asked noted zoologist Ray Lankester to select some excerpts from the encyclopedia.

Here, he has selected excerpts from the entry for The Intelligence of Animals. Since the 1911 edition of the encyclopedia is now public domain, you can read the full entry as it originally appeared in print. And for comparison, here is the Wikipedia entry on Animal Intelligence.

HOW THE BRAINS OF ANIMALS WORK (PDF)

From February 12, 1911