CHAPTER II.

THE MEANS OF DISPERSAL AND THE MIGRATIONS OF ANIMALS.

Means of Dispersal of Mammalia (p. 10)--Climate as a Limit to the Range of Mammals (p. 11)--Valleys and Rivers as Barriers to Mammals (p. 12)-- Arms of the Sea as Barriers to Mammals (p. 13)--Ice-floes and drift-wood as aiding the Dispersal of Mammals (p. 14)--Means of Dispersal of Birds (p. 15)--Dispersal of Birds by Winds (p. 16)--Barriers to the Dispersal of Birds (p. 17)--The Phenomena of Migration (p. 18)--Migrations of Birds (p. 19)--General remarks on Migration (p. 25)--Means of Dispersal of Reptiles and Amphibia (p. 28)--Means of Dispersal of Fishes (p. 29)-- Means of Dispersal of Mollusca (p. 30)--Means of Dispersal of Insects and the Barriers which limit their Range (p. 32) 10-34