“The _Review of Comparative Biology_ in its October issue contained a short and modest paper over the name of Henry Upton which is destined to influence modern thought more profoundly than anything that has appeared since _Lux Mundi_ or the _Origin of Species_. Henry Upton has been taken from us. Or, to use a phrase consecrated by his own reverent quotation of it, he has ‘Passed beyond the Veil,’ he has crossed the bar; but short as the time is since this brief essay was given to the world, his name is already famous. “You will have heard the echoes of passionate discussions upon his famous theory; it is my business this afternoon to put before you in clear and popular language that you can easily understand, what that theory was; and when I have done so I make no doubt that you will see why it has been thought so transcendently important. “Briefly, Henry Upton declared himself finally convinced that between Man and the Simius Gabiensis there existed a differentiation so marked as to destroy all possibility of any recent common origin for the two species. “When I add that Simius Gabiensis is but the technical name for the Ringtailed Baboon of our childhood you will at once appreciate what a revolution such a pronouncement must work if it can be sustained: and it has been sustained! “It is common knowledge and will be familiar to the youngest child in this room that the Ringtailed Baboon is the highest of the Anthropoids, and the one nearest approaching the majesty of the Human Species--Homo Sapiens; and if between him and ourselves the link of affinity prove far removed, it seems indeed as though the whole edifice of modern biology and of modern thought itself will fall to the ground. “The superficial differences to be discovered between a cleanly and well-bred gentleman and the Ringtailed Baboon are common property: the beard in the Anthropoid is not so clearly defined as in the allied organism of Man, but covers the whole face; the superciliary arch is more prominent, the diaphragm tessarated and refulgent, while the Cardiac Aneries are at once paler and less vasculate in form: the rings upon the tail are of course peculiar to the Simian, and almost universally absent in the human species, while the speech of the latter is far more complex and articulate than that of the former. “But I need not detain this cultured audience with considerations quite unworthy of physical science. All the weight of real evidence pointed to the close relationship between the two types, and it was a commonplace of the classroom that in all fundamentals the two animals betrayed an ancestor less remote than that of the dog and the wolf. Now, since Henry Upton’s work appeared, we are certain that that ancestor is more remote than the ancestor of the hippopotamus and the Jersey cow, and probably more remote than that of the mongoose and the Great Auk.