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Albian American anatomy ancestor animals appear Association atavism beds biological birds botany British Museum cells Cenomanian central characters chlorophyll collection coloured connection contains Cretaceous deposits depth described diatom eggs eskers evidence evolution experiments fact fauna feet female fish flora foraminifera formation fossils Gault genera genus Geological geologists glauconite groups illustrated important individual insects interesting island known larva Lauterborn Lepidoptera less London Lower male mammals marine matter method Natural History Natural Science natural selection naturalists nervure neuration notochord Nymphalids observed obtained occur ontogeny organs origin palaeontology Palaeozoic paper Papilionids plants pouch present probably Prof Professor protoplasm published recent reference regard remarkable rocks Rotifera rotifers scientific Silurian Society species specimens stroke structure text-books theory tion University variations vertebrates vibrations volume zone Zoological zoology
Página 66 - Published under the direction of the general council of medical education and registration of the United Kingdom, pursuant to the medical act (1858).
Página 267 - Previous experience makes a difference in the quickness with which the cat forms the associations. After getting out of six or eight boxes by different sorts of acts the cat's general tendency to claw at loose objects within the box is strengthened and its tendency to squeeze through holes and bite bars is weakened ; accordingly it will learn associations along the general line of the old more quickly.
Página 266 - When put into the box the cat would show evident signs of discomfort and of an impulse to escape from confinement.
Página 342 - Under changed conditions of life, it is at least possible that slight modifications of instinct might be profitable to a species ; and if it can be shown that instincts do vary ever so little, then I can see no difficulty in natural selection preserving and continually accumulating variations of instinct to any extent that was profitable. It is thus, as I believe, that all the most complex and wonderful instincts have originated.
Página 12 - I'd take it kindly if you'd send the pieces Home to old Missouri I
Página 343 - When, at last, the filling was level with the ground, she brought a quantity of fine grains of dirt to the spot and picking up a small pebble in her mandibles, used it as a hammer in pounding them down with rapid strokes, thus making this spot as hard and firm as the surrounding surface.
Página 342 - The general impression that remains with us as a result of our study of these activities is that their complexity and perfection have been greatly overestimated. We have found them in. all stages of development and are convinced that they have passed through many degrees, from the simple to the complex, by the action of natural selection. Indeed, we find in them beautiful examples of the survival of the fittest.
Página 266 - It tries to squeeze through any opening ; it claws and bites at the bars or wire ; it thrusts its paws out through any opening, and claws at everything it reaches; it continues its efforts when it strikes anything loose and shaky : it may claw at things within the box. It does not pay very much attention to the food outside, but seems simply to strive instinctively to escape from confinement. The vigour with which it struggles is extraordinary. For eight or ten minutes it will claw, and bite, and...
Página 267 - ... felt as to be done or as doing is in animals the important thing, is the thing which gets associated, while the act as done, as viewed from outside, is a secondary affair. I prefer to have a separate word, impulse, for the former, and keep the word act for the latter, which it commonly means.
Página 272 - ... give to it. Sometimes one gets this animal consciousness while in swimming, for example. One feels the water, the sky, the birds above, but with no thoughts about them or memories of how they looked at other times, or aesthetic judgments about their beauty ; one feels no ideas about what movements he will make, but feels himself make them, feels his body throughout. Self-consciousness dies away. Social consciousness dies away. The meanings, and values, and connections of things die away. One...