CONTENTS. 
IX 
CHAPTEE XIL 
Geogeaphical Distkibution —con tinned . 
Distribution of fresli-water productions — On the inhabitants of 
oceanic islands — Absence of Batrachians and of terrestrial Mam¬ 
mals — On the relation of the inhabitants of islands to those of 
the nearest mainland — On colonisation from the nearest source 
with subsequent modificationSummary of the last and pre¬ 
sent chapters .Page 383-410 
CHAPTEE XIIL 
Mutual Affinities of Okganic Beings : Morphology : 
Embryology : Kudimentary Organs. 
Classification, groups subordinate to groups— Natural system — 
Rules and difficulties in classification, explained on the theory of 
descent with modification — Classification of varieties — Descent 
always used in classification — Analogical or adaptive characters 
— Affinities, general, complex and radiating — Extinction se¬ 
parates and defines groups —■ Morphology, between members 
of the same class, between parts of the same individual — 
Embryology, laws of, explained by variations not supervening 
at an early age, and being inherited at a corresponding age 
— Rudimentary organs ; their origin explained — Summary 
411-458 
CHAPTEE XIV. 
Recapitulation and Conclusion. 
Recapitulation of the difficulties on the theory of Natural Selection 
— Recapitulation of the general and special circumstances in its 
favour — Causes of the general belief in the immutability of 
species — How far the theory of natural selection may be 
extended — Effects of its adoption on the study of Natural 
history — Concluding remarks . 459-490 
Index 
491 ' 
5 
