In a letter of August 13th, 1869, Sir J.D.Hooker wrote correcting Mr.
Darwin's impression: "I did not mean to imply that Hallett affirmed that all variation stopped--far from it: he maintained the contrary, but if I understand him aright, he soon arrives at a point beyond which any further accumulation in the direction sought is so small and so slow that practically a fixity of type (not absolute fixity, however) is the result.") It is a grand fact about Anoplotherium (230/2.

This perhaps refers to the existence of Anoplotherium in the S.American Eocene formation: it is one of the points in which the fauna of S.America resembles Europe rather than N.America.

(See Wallace "Geographical Distribution," I., page 148.)), and shows how even terrestrial quadrupeds had time formerly to spread to very distinct regions.

At each epoch the world tends to get peopled pretty uniformly, which is a blessing for Geology.
The article in "N.

British Review" (230/3.