Liverpool Courier.—­“Contains a great deal of well-marshalled observation.”

Lancet.—­“A very interesting book ... simply and clearly written.”

Dundee Advertiser.—­“... a book which is at the same time one of the most interesting and readable on the controversial aspects of natural history published in recent years.”

The Christian World.—­“This very interesting work.”

Bristol Times.—­“A work of value, which will give occasion to many to think, and an admirable presentation of facts.”

Westminster Review.—­“... written in popular language and contains many original observations.”

Daily Chronicle.—­“An interesting and suggestive book.”