Proceedings of the Academy of Natural Sciences of Philadelphia, Volume 36

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Academy of Natural Sciences of Philadelphia, 1885 - Electronic journals
"Publications of the Academy of Natural Sciences of Philadelphia": v. 53, 1901, p. 788-794.
 

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Page 300 - IF IT could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.
Page 300 - TO SUPPOSE that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different amounts of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree.
Page 362 - Memoranda of the origin, plan, and results of the field and other experiments conducted on the farm and in the laboratory of Sir JB Lawes at Rothamsted, Herts.
Page 330 - Washington in every block, cause constant wear and tear to both horse and vehicle ; it is to be hoped that at no very distant day the drainage of the entire city will be underground, and that a more even surface for driving may be obtained. The streets of a city are public property , in which all citizens are more or less interested, and in point of necessity no other public work can equal them ; why, then, is not more attention...
Page 300 - Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist; if further, the eye does vary ever so slightly, and the variations be inherited, which is certainly the case; and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection,...
Page 18 - This continues until the parent body is much reduced in size, when the rays again protrude and the animal returns to its normal condition. The third mode of reproduction is by the formation and liberation of minute germs. In this state, also, the rays are not withdrawn, but the body of the Clathrulina becomes filled with minute green particles, which, even before liberation, exhibit active motion. A number of these are expelled, enclosed in a thin protoplasmic film or globular sac, which bursts shortly,...
Page 10 - Experiments on these forms show their sensitiveness to light and shadow, and the cells showing the retinal character described leaves little doubt as to the power of vision. No nerves could be demonstrated passing direct to these cells, and probably those distributed to the general epidermis serve in transmitting the impressions. The visual power is so low that nerves have not been yet specialized for this purpose.
Page 324 - Act of the General Assembly of the Commonwealth of Pennsylvania, entitled "An Act to provide for the incorporation and Regulation of certain corporations...
Page 300 - ... animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, should not be considered as subversive of the theory. How a nerve comes to be sensitive to light, hardly concerns us more than how life itself originated...
Page 29 - While considering the effect of the presence of so large a sponge-growth at the very inlet to the supply-pumps, Mr. Potts stated that this particular species was conspicuous among the known North American sponges by its great relative density and the small proportion of its sarcode or flesh. Its decay, therefore, at the termination of its period of summer growth would be a less cause of pollution to the water-supply than that of any other sponge Moreover, from recent investigations into the...

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