The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life / by Charles Darwin.

Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: The origin of species by means of natural selection, or, The preservation of favoured races in the struggle for life / by Charles Darwin. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

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    CHAPTER X. On the Imperfection of the Geological Record. On the absence of intermediate varieties at the present day—On the nature of extinct intermediate varieties ; on their number— On the lapse of time, as inferred from the rate of denudation and of deposition—On the lapse of time as estimated by years—On the poorness of our paleonto- logical collections—On the intermittence of geological formations—On the denudation of granitic areas—On the absence of intermediate varieties in any one formation—On the sudden appearance of groups of species— On their sudden appearance in the lowest known fossiliferous strata— Antiquity of the habitable earth Page 247 CHAPTER XI. On the Geological Succession of Organic Beings. On the slow and successive appearance of new species—On their different rates of change—Species once lost do not reappear—Groups of species follow the same general rules in their appearance and disappearance as do single species—On extinction—On simultaneous changes in the forms of life throughout the world—On the affinities of extinct species to each other and to living species—On the state of development of ancient forms —On the succession of the same types within the same areas—Summary of preceding and present chapter .. .. .. .. .. 272 CHAPTER XII. Geographical Distribution. Present distribution cannot be accounted for by differences in physical con- ditions—Importance of barriers —Affinity of the productions of the same continent—Centres of creation—Means of dispersal, by changes of climate and of the level of the land, and by occasional means—Dispersal during the Glacial period—Alternate Glacial periods in the north and south 29G CHAPTER XIII. Geographical Distribution—continued. Distribution of fresh-water productions—On the inhabitants of oceanic islands —Absence of Batrachians and of terrestrial Mammals—On the relation of the inhabitants of islands to those of the nearest mainland—On colonisation from the nearest source with subsequent modification—Summary of the last and present chapter .. .. .. . .. • • 322