The Doctrine of Descent and DarwinismH. S. King & Company, 1875 - Всего страниц: 334 |
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according adaptation already Ammonites Amphibians animal world apes appearance Ascidian become birds bone brain causes Cetacea character characteristics comparative anatomy complete connection continent Darwin dentition derivation diverge doctrine of Descent Echinoderms embryonic Eocene exhibit existence external facts families fauna fish formation fossil Ganoids Gastrula gemmules genera genus geological Goethe grade gradually groups Haeckel heredity higher horse hypothesis idea individual infer intermediate forms islands lancelet language larva larvæ likewise linguistic lower mammals manifest Marsupials Medusa ment merely metamorphosis modifications morphological mutability natural selection naturalist observations Oolite organisms origin ovum peculiar pedigree perfect period phase phenomena placenta plants polypes possess present primordial progenitors races regard relations remains reproduction reptiles Rütimeyer says scarcely separate sexual Silurian skull species strata structure systematic terrestrial animals Tertiary theory of selection tion transformation transition Ungulata Ungulates varieties vertebral column Vertebrata vertebrate animals whole
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Стр. 162 - There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved.18 Darwin always knew that his views would be controversial. A few days before The Origin of Species appeared, Darwin wrote, in a letter to Wallace, 'God knows what...
Стр. 145 - It may metaphorically be said that natural selection is daily and hourly scrutinizing, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
Стр. 143 - Near villages and small towns I have found the nests of humble-bees more numerous than elsewhere, which I attribute to the number of cats that destroy the mice." Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine, through the intervention first of mice and then of bees, the frequency of certain flowers in that district!
Стр. 160 - I had not formerly sufficiently considered the existence of many structures which appear to be, as far as we can judge, neither beneficial nor injurious ; and this I believe to be one of the greatest oversights as yet detected in my work.
Стр. 160 - Na'geli on plants, and the remarks by various authors with respect to animals, more especially those recently made by Professor Broca, that in the earlier editions of my Origin of Species I perhaps attributed too much to the action of natural selection or the survival of the fittest.
Стр. 132 - ... Having attended to the habits of animals and their relations to the surrounding conditions, I was able to realize the severe struggle for existence to which all organisms are subjected ; and my geological observations had allowed me to appreciate to a certain extent the duration of past geological periods. With my mind thus prepared I fortunately happened to read Malthus's Essay on Population ; and the idea of natural selection through the struggle for existence at once occurred to me.
Стр. 142 - Hence we may infer as highly probable that, if the whole genus of humble-bees became extinct or very rare in England, the heartsease and red clover would become very rare, or wholly disappear. The number of humble-bees in any district depends in a great measure on the number of fieldmice, which destroy their combs and nests ; and Col.
Стр. 141 - Perhaps Paraguay offers the most curious instance of this ; for here neither cattle, nor horses, nor dogs have ever run wild, though they swarm southward and northward in a feral state ; and Azara and Rengger have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born.