PREFATORY NOTE
I have alluded to final causes in this address. The origin of things is seldom other than enigmatic, and were I to be asked why the Harveian Oration for 1912 was written by me I should have to reply: A leading article in the Lancet, the Reports of the Imperial Cancer Research Fund, and what I believe to have been a telepathic transit between our President and myself, share the responsibility.
In republishing it for circulation in the College I can only hope that it may give some pleasure to those who read it, perhaps even here and there some stimulus to thought, ere it receive sepulture within the Library of our College, a tomb of the most honourable magnificence.
