In some cases a prediction has been verified, in others an appeal has been successful; and in regard to some few matters touched on, new views have taken the place of those adopted when my statement was originally made. I have added notes explanatory of such changes where they are actually necessary.

E. RAY LANKESTER.

December 1889.

I

DEGENERATION:

A CHAPTER IN DARWINISM

DELIVERED AS ONE OF THE EVENING LECTURES AT THE SHEFFIELD MEETING OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF

SCIENCE, 22D AUGUST 1879, UNDER THE PRESIDENCY OF PROFESSOR ALLMAN, LL.D., F.R.S.

B