The Shipley Collection of Scientific Papers, Volumen231897 |
Dentro del libro
Resultados 1-5 de 51
Página 883
... theory of " the continuity of the germ - plasm , " is presumed to explain adequately the reduction of useless organs , and the occurrence , especially among domesticated animals , of " the greater number of those variations which are ...
... theory of " the continuity of the germ - plasm , " is presumed to explain adequately the reduction of useless organs , and the occurrence , especially among domesticated animals , of " the greater number of those variations which are ...
Página 884
... theory of the " Cessation of Selection " ( 74 ) . In 1890 Romanes revised his earlier views , calling especial attention to the points in which they differed from those of Darwin and Weismann , and in 1895 , in his posthumous work , the ...
... theory of the " Cessation of Selection " ( 74 ) . In 1890 Romanes revised his earlier views , calling especial attention to the points in which they differed from those of Darwin and Weismann , and in 1895 , in his posthumous work , the ...
Página 892
... theory , ought not to be the purpose of biological investigation . The relation that the facts may have to other facts and the bearing that they may have upon collateral theories should , at least , be indicated . The following ...
... theory , ought not to be the purpose of biological investigation . The relation that the facts may have to other facts and the bearing that they may have upon collateral theories should , at least , be indicated . The following ...
Página 2
... theory as applied to development . The results of a re - examination of the history of these small cells in Nereis , taken in connection with other recent studies in cell - lineage , lend strong support to the conclusion indicated above ...
... theory as applied to development . The results of a re - examination of the history of these small cells in Nereis , taken in connection with other recent studies in cell - lineage , lend strong support to the conclusion indicated above ...
Página 25
... theory as applied to development has been very ably urged , especially by Whitman and by Adam Sedgwick ; and their ... theory in this aspect ; and it may well be questioned whether in the reaction against the cell - mosaic theory , as ...
... theory as applied to development has been very ably urged , especially by Whitman and by Adam Sedgwick ; and their ... theory in this aspect ; and it may well be questioned whether in the reaction against the cell - mosaic theory , as ...
Términos y frases comunes
American eggs Amphioxus animals annelids appear Appendicularia archenteron Aricia arrangement autotomy axis-cylinder process bones buds cave-earth cavern cell body cell of Helix cell-lineage cells of Invertebrates cellular centrosomes character chromophilous chromophilous granules chromosomes colonial condition curve density depth determined differentiation direction disease distilled water division ecdysis embryo entoblastic evidence existence fact fathoms fibrils FLEMMING'S foliage-leaves function ganglion cells gasteropods geological germ-plasm give granular rows ground-substance growth haematoxylin Heredity hydrometer individual investigation large number latter leaves Leptoplana mesoblast-bands mesoblasts metamorphosis method methylen blue morphological Museum naturalists Nereis nerve cells neuroglia neuroglia fibrils nucleus observations ocean offspring organs origin plant plate polyclade position posterior present primary mesoblasts produce quartet regard reproductive cells safranin segmentation segmentation nucleus slug solution species specimens spindles spiral sporophyll stained stalagmite stem structure substance surface tarsus temperature theory tion tissues variations Vertebrates
Pasajes populares
Página 7 - I happened to read for amusement 'Malthus on Population', and being well prepared to appreciate the struggle for existence which everywhere goes on from long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed. The result of this would be the formation of new species. Here then I had at last got a theory by which to work...
Página 2 - And pretty dwarfs to show the way Through fairy hills and fairy dales. But when a bad child goes to bed, From left to right she weaves her rings, And then it dreams all through the night Of only ugly horrid things ! Then lions come with glaring eyes, And tigers growl, a dreadful noise, And ogres draw their cruel knives, To shed the blood of girls and boys.
Página 2 - LITTLE fairy comes at night, Her eyes are blue, her hair is brown, With silver spots upon her wings, And from the moon she flutters down. She has a little silver wand, And when a good child goes to bed She waves her wand from right to left, And makes a circle round its head.
Página 11 - human remains and works of art, such as arrow-heads and knives of flint, occur in all parts of the cave and throughout the entire thickness of the clay : and no distinction founded on condition, distribution, or relative position, can be observed, whereby the human can be separated from the •other reliquiae," which included bones of the "elephant, rhinoceros, ox, deer, horse, bear, hyaena, and a feline animal of large size.
Página 4 - Les noms géographiques des nations qui emploient, dans leur écriture, des caractères latins (langues néo-latines, germaniques, Scandinaves), seront écrits avec l'orthographe de leur pays d'origine. Les règles qui vont suivre s'appliquent uniquement aux noms géographiques de pays qui n'ont point d'écriture propre ou qui écrivent avec des caractères différents des caractères latins. Toutefois, à titre exceptionnel, on conservera l'orthographe usitée pour les noms de lieux, lorsqu'elle...
Página 8 - It may well be doubted ; and yet one is always the better for a walk in the morning air, — a medicine which may be taken over and over again without any sense of sameness, or any failure of its invigorating quality.
Página 12 - Whatever other causes have been at work, natural selection is supreme, to an extent which even Darwin himself hesitated to claim for it. The more we study it the more we are convinced of its overpowering importance, and the more confidently we claim, in Darwin's own words, that it ' has been the most important, but not the exclusive, means of modification...