81

A profound consideration of method by which races of men have been exterminated (see Pritchards paper) (Ed. Phil. Journ. end of 1839) very important. it seems owing to immigration of other races, so it is with domestic breeds. (though in this case crossing has had somewhat to do with it. mem. dogs & pigs in Polynesia; & dogs in S. America Rengger.

— now it is this very immigration which tends to make the destroyers vary; so that we here see reasons — why no perfect gradation can be expected in any one country. — in a descending series of strata

(22)

This again shows how much forms depend on other forms

89

Lyell's Paper, in Taylor's Journ. — Phil. Mag. May. 1840 p. 362. — some Mammals of Norfolk Crag. mentioned — allied Beaver to present forms. — —

How many tertiary estuary & Lacrustine formations contain fossils, — mammals — a few only — & how many estuary formations are there in old Secondary Series — few —

91

Maer June /41/, observed 3 plants of Caltha Palustris alone together. one had seed-pods turning brown, whilst both others were in nearly full flower