Lectures on the Darwinian theory / delivered by Arthur Milnes Marshall ; edited by C.F. Marshall.

Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the Darwinian theory / delivered by Arthur Milnes Marshall ; edited by C.F. Marshall. 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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    Natural Selection: the keynote of the Darwinian Theory. The fittest to survive are not necessarily those which are ideally most perfect. Changes in environment. Geological evidence of changes of climate in England and in Greenland. Comparison between Natural and Artificial Selection. Natural Selection acts for the good of the Species. Artificial Selection is directed solely towards the benefit or the pleasure of Man. LECTURE III. (Pp. 53-77.) THE ARGUMENT FROM PALEONTOLOGY. The Structure of the Earth's Crust. A series of superposed layers or strata, composed of various materials, originally deposited for the most part under water, and subsequently raised above the surface. Fossils are the actual remains, as bones, teeth, shells, etc., or the indications, as, e.g., footprints, of the animals that formerly in- habited the earth. Amongst them, were our collections com- plete, would be the entire series of the ancestors of all living animals. The actual age of Fossils cannot be determined, but their relative ages are known from the position of the strata in which they are found. The Imperfection of the Geological Record. Only certain parts of certain animals can be preserved as fossils : special conditions are necessary for their preservation, and for their subsequent exposure at places accessible to man. It is irrational to expect fossils to yield continuous series of forms, save under exceptional circumstances. A Chapter of Accidents. The Geological Evidences of Evolution. Life on the earth has been continuous. Cuvier's Cataclysms have no place in nature. In passing from the older to the more recent strata, there is a general advance in organisation, and a gradual approach towards the existing condition. Fossils are generaUzed forms rather than directly intermediate links. The geological history of the Horse, of Birds and Reptiles, and of Paludina. Extinction of Species. Persistent types. Comparison of the Geological Record with the History of Man.