 | 1860 - Страниц: 890
...sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different...intently watching each slight accidental alteration which, under varied circumstances, may in any way or in any degree tend to produce a distincter image.... | |
 | 1861 - Страниц: 842
...sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thickne>seB, placed at different distances from each other, and with the surfaces of each 'layer slowly... | |
 | Charles Darwin - 1864 - Страниц: 472
...sensitive to light beneath, and men suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different...slight accidental alteration in the transparent layers; ana carefully selecting each alteration -which, under varied circumstances, may in any way, or in any... | |
 | Paul Janet - 1866 - Страниц: 216
...must compare the eye to an optical instrument," he says, " we ought in imagination to take a third layer of transparent tissue, with a nerve sensitive...surfaces of each layer slowly changing in form."* What a number of suppositions and of coincidences we must admit here ! But, even if we grant these... | |
 | Charles Darwin - 1866 - Страниц: 668
...this layer to be continually changing slowly in density, so as to separate into layers of diiferent densities and thicknesses, placed at different distances...form. Further we must suppose that there is a power (natural selection) always intently watching each slight accidental alteration in the transparent layers... | |
 | Paul Janet - 1867 - Страниц: 214
...must compare the eye to an optical instrument," he says, " we ought in imagination to take a third layer of transparent tissue, with a nerve sensitive...surfaces of each layer slowly changing in form."* What a number of suppositions and of coincidences we must admit here ! But, even if we grant these... | |
 | 1867 - Страниц: 510
...nerve sensitive to light beneath, and suppose every part of the layer to be continually changing slowly in density, so as to separate into layers of different...form. Further we must suppose that there is a power (natural selection) always intently watching each slight accidental alteration in the transparent layers,... | |
 | Robert Mackenzie Beverley - 1867 - Страниц: 424
...sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density so as to separate into layers of different...placed at different distances from each other, and with surfaces of each layer slowly changing in form. Farther, we may suppose that there is a potver, Natural... | |
 | Robert Mackenzie Beverley - 1867 - Страниц: 406
...sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density so as to separate into layers of different...placed at different distances from each other, and with surfaces of each layer slowly changing in form. Farther, we may suppose that there is a power, Natural... | |
 | Robert Mackenzie Beverley - 1867 - Страниц: 598
...of the eye as an optical instrument, that we are to ' suppose there is a power, Natural Selection, always intently watching each slight accidental alteration...layers, and carefully selecting each alteration which may in any wny produce a distinctive image,' &c. (208). This power, therefore, is to all intents and... | |
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... with a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thicknesses, placed at different distances from each other, and... 
