HKB
ON THE ORIGIN OF SPECIES BY VARIATION AND NATURAL SELECTION.
Mr. Darwin's Theory of the Origin of Species by Natural Selection. Memoir by Mr. Wallace. Manner in which favoured Races prevail in the Struggle for Existence. Formation of new Races by breeding. Hypotheses of definite and indefinite Modifiability equally arbitrary. Competition and Extinction of Races. Progression not a necessary Accompaniment of Variation. Distinct Classes of Phenomena which Natural Selection explains. Unity of Type, Rudimentary Organs, Geographical Distribution, Relation of the extinct to the living Fauna and Flora, and mutual Relations of successive Groups of Fossil Forms. Light thrown on Embryological Development by Natural Selection. Why large Genera have more variable Species than small ones. Dr. Hooker on the Evidence afforded by the Vegetable Kingdom in favour of Creation by Variation. Steenstrup on alternation of Generations. How far the Doctrine of Independent Creation is opposed to the Laws now governing the Migration of Species.
CHAP. 22.
OBJECTIONS TO THE HYPOTHESIS OF TRANSMUTATION CONSIDERED.
Statement of Objections to the Hypothesis of Transmutation founded on the Absence of Intermediate Forms. Genera of which the Species are closely allied. Occasional Discovery of the missing Links in a Fossil State. Davidson's Monograph on the Brachiopoda. Why the Gradational Forms, when found, are not accepted as Evidence of Transmutation. Gaps caused by Extinction of Races and Species. Vast Tertiary Periods during which this Extinction has been going on in the Fauna and Flora now existing. Genealogical Bond between Miocene and Recent Plants and Insects. Fossils of Oeningen. Species of Insects in Britain and North America represented by distinct Varieties. Falconer's Monograph on living and fossil Elephants. Fossil Species and Genera of the Horse Tribe in North and South America. Relation of the Pliocene Mammalia of North America, Asia, and Europe. Species of Mammalia, though less persistent than the Mollusca, change slowly. Arguments for and against Transmutation derived from the Absence of Mammalia in Islands. Imperfection of the Geological Record. Intercalation of newly discovered Formation of intermediate Age in the chronological Series. Reference of the St. Cassian Beds to the Triassic Periods. Discovery of new organic Types. Feathered Archaeopteryx of the Oolite.
CHAP. 23.
ORIGIN AND DEVELOPMENT OF LANGUAGES AND SPECIES COMPARED.
Aryan Hypothesis and Controversy. The Races of Mankind change more slowly than their Languages. Theory of the gradual Origin of Languages. Difficulty of defining what is meant by a Language as distinct from a Dialect. Great Number of extinct and living Tongues. No European Language a Thousand Years old. Gaps between Languages, how caused. Imperfection of the Record. Changes always in Progress. Struggle for Existence between rival Terms and Dialects. Causes of Selection. Each Language formed slowly in a single Geographical Area. May die out gradually or suddenly. Once lost can never be revived. Mode of Origin of Languages and Species a Mystery. Speculations as to the Number of original Languages or Species unprofitable.
CHAP. 24.
BEARING OF THE DOCTRINE OF TRANSMUTATION ON THE ORIGIN OF MAN, AND HIS PLACE IN THE CREATION.