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abalone acid acquired characters American animal antenna appear appendages Arachnids Arthropods birds body Bull cave cells Chilopods cleavage color Cretaceous Crustacea crystals described diabase dorsal ectoderm embryo energy evidence evolution Extr eyes fact fauna feet Fish formation fossil genera genus Geol Geological gland Hemipenis Hexapods Indiana insects Island karyoplasm known Lake larva later layer leucocytes Living Age mass ment Mesozoic metacarpal mineral Miocene molar Museum natural Naturalist nephridia neuromeres North nuclein nucleus observations organs origin paper physiology plagioclase plants plate Pliocene portion posterior premolar present probably Prof Professor protoplasm pupa pyroxene quartz recent regard region Report represented River rocks shell shell-heaps side South species specimens spines strawberry structure surface Surv Teleoceras tion tissue Trilobites U. S. Natl upper variation Weismann Zool
Página 364 - Printing-House, between the hours of ten in the morning and two in the afternoon, to preach eight Divinity Lecture Sermons, the year following, at St.
Página 663 - Can it, then, be thought improbable, seeing that variations useful to man have undoubtedly occurred, that other variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of thousands of generations...
Página 988 - Mackintosh as proof that a period of not more than 6000 years has elapsed since the boulders were left in their positions. The vertical extent of this denudation, averaging about six inches, is nearly the same with that observed in the southwest part of the Province of Quebec by Sir William Logan and Dr. Robert Bell, where veins of quartz marked with glacial strife stand out to various heights not exceeding one foot above the weathered surface of the enclosing limestone.
Página 663 - On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed. This preservation of favorable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest...
Página 552 - for the advancement and prosecution of scientific research in its broadest sense," now amounts to $25,000. As the income is already available, the trustees desire to receive applications for appropriations in aid of scientific work. This endowment is not for the benefit of any one department of science, but it is the intention of the trustees to give the preference to those investigations...
Página 204 - A member of the Anthropological Society of Washington "has placed in the hands of the Treasurer of the Society a "sum of money to be awarded in prizes for the clearest "statements of the elements that go to make up the most "useful citizen of the United States, regardless of occupation.
Página 783 - Congress. 501 Books, maps, music, engravings, photographs, etchings, bound or unbound, and charts which shall have been printed more than twenty years at the date of importation, and all hydrographic charts and publications issued for their subscribers, or exchanges by scientific and literary associations or academies, or publications of individuals for gratuitous private circulation, and public documents issued by foreign governments.
Página 924 - ... which strikes our senses. At the same time they are compelled to add, since it is an important observation, that the contact and repeated excitement of the imagination which produce the crises may become hurtful ; that the spectacle of these crises is likewise dangerous on account of the imitative faculty which is a law of nature, and consequently that all treatment in public in which magnetism is employed must, in the end, be productive of evil results.
Página 983 - Tertiary periods at lower altitudes, and its surface was largely enveloped by residual clays and by alluvial sand and gravel. With the elevation of the continent, increased rainfall and snowfall and resulting river floods swept away these superficial materials from the higher lands and spread them on the coastal plain and along the Mississippi valley, where the streams expanded over broad areas with shallow and slackened currents. As the elevation increased, however, the rivers would attain steeper...