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according action adaptation allied Amblystoma Amblystoma form Amphibia animal appear arises Axolotl butterflies caterpillar causes centim certainly characters colour completely conceivable constant Darwin Deilephila depends dimorphic Diptera direction divergence dorsal Dumeril entirely Eueides Eueides Isabella existence explained extent external conditions external influences eye-spots fact families food-plant form-divergence form-relationship further genera Genoese genus gills green Hartmann heredity Hymenoptera imago incongruence individual insects instance lake large number larvae last stage latter Lepidoptera manner marking mechanical metamorphosis Mexican millim mode morphological morphosis moult Natural length natural selection Nymphalideous observations occur ocelli ontogeny organism perennibranchiate period phenomena phyletic development phyletic stage phyletic vital force phytophagic possess present principle processes pupa reproduction result reversion ring-spots salamander segments sexual shown similar Siredon species specimens spines spots sterility stomas structure sub-order subdorsal line systematic groups teleological theory tion Triton unequal Vanessa variability variations varieties whilst whole
Сторінка 710 - Certainly not ; it would be a great delusion if any one were to believe that he had arrived at a comprehension of the universe by tracing the phenomena of nature to mechanical principles.
Сторінка 716 - Mechanism and teleology do not exclude one another, they are rather in mutual agreement. Without teleology there would be no mechanism, but only a confusion of crude forces; and without mechanism there would be no teleology, for how could the latter otherwise effect its purpose ? 1* Von Hartmann correctly says : — " The most 10 See Von Hartmann, loc. cit. p. 158. complete mechanism conceivable is likewise the most completely conceivable teleology.
Сторінка 718 - The final and main result of this essay will thus be found in the attempted demonstration that the mechanical conception of Nature very well admits of being united with a teleological conception of the Universe.
Сторінка 523 - ... numerous small black dots, but on each of the following five segments there were but two such dots. A pale longitudinal line ran above the yellow patches, and the head and first joint were uniformly dull reddishbrown. The most common general color of the full grown worm is a rich velvety vinous-brown. When at rest, it draws back the fore part of the body, and retracts the . head and first two joints into the third (fig.
Сторінка 630 - Those that 1 kept well fed iu jars and seldom changed the water, say once in three days, usually began to show a slight change in from two to three weeks, and all of them completed the change into the Amblystoma inside of six weeks, while I have had but three changes of those kept in the cauf (sixty of them) in three months. During that time they have not been fed at all. The Siredon...
Сторінка 523 - Larva. wards, the larva is green, with a tinge of pink along the sides, and with an immensely long straight pink horn at the tail. This horn begins to shorten, and finally curls round like a dog's tail, as at figure 139, c.
Сторінка 523 - It measures about three and one-half inches when crawling, which operation is effected by a series of sudden jerks. The third segment is the largest, the second but half its size, and the first still smaller, and when at rest the two last mentioned segments are partly withdrawn into the third. The young larva is green, with a long slender reddish horn rising from the eleventh segment and curving over the back...
Сторінка 431 - ... influence of external conditions, whether acting, as Mr. Darwin has suggested, through natural selection, or in any other manner, will see no reason why these changes should be confined to the mature animal. And it is evident that creatures which, like the majority of insects, live during the successive periods of their existence in very different circumstances, may undergo considerable changes in their larval organization, in consequence of forces acting on them while in that condition ; not,...
Сторінка 712 - ... behind the cooperating forces of nature which " aim at a purpose " must we admit a Cause, which is no less inconceivable in its nature, and of which we can only say one thing with certainty, viz., that it must be teleological.
Сторінка 527 - It is possible that this horn, which was formerly possessed by the ancestors of the Sphingidce, and which is now retained in many genera, is a remnant of a flagellate organ having a similar function to the headtentacles of the /Vz/z/w-larvae, or to the caudal appendages of Dicranura (see p.