Life and Evolution: An Introduction to General Biology

Передняя обложка
Harcourt, Brace, 1926 - Всего страниц: 449

Результаты поиска по книге

Другие издания - Просмотреть все

Часто встречающиеся слова и выражения

Популярные отрывки

Стр. 422 - Of all the western stars, until I die. It may be that the gulfs will wash us down: It may be we shall touch the Happy Isles, And see the great Achilles, whom we knew. Tho' much is taken, much abides; and tho...
Стр. 349 - I look at the geological record as a history of the world imperfectly kept, and written in a changing dialect; of this history we possess the last volume alone, relating only to two or three countries. Of this volume, only here and there a short chapter has been preserved; and of each page, only here and there a few lines.
Стр. 392 - It may metaphorically be said that natural selection is daily and hourly scrutinizing, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and sensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
Стр. 392 - ... those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life. We see nothing of these slow changes in progress until the hand of time has marked the lapse of ages, and then so imperfect is our view into long-past geological ages that we see only that the forms of life are now different* from what they formerly were.
Стр. 247 - Battle within battle must ever be recurring with varying success; and yet in the long-run the forces are so nicely balanced, that the face of nature remains uniform for long periods of time, though assuredly the merest trifle would often give the victory to one organic being over another.
Стр. 395 - Given any species in any region, the nearest related species is not likely to be found in the same region nor in a remote region, but in a neighboring district separated from the first by a barrier of some sort.
Стр. 10 - Life is a series of definite and successive changes, both of structure and composition, which take place within an individual without destroying its identity.
Стр. 247 - Azara and Rengger have shown that this is caused by the greater number in Paraguay of a certain fly, which lays its eggs in the navels of these animals when first born. The increase of these flies, numerous as they are, must be habitually checked by some means, probably by other parasitic insects. Hence, if certain insectivorous birds were to decrease in Paraguay, the parasitic insects would probably increase; and this would lessen the number of the navel-frequenting flies — then cattle and horses...
Стр. 247 - Scotch fir ; but in several parts of the world insects determine the existence of cattle. Perhaps Paraguay offers the most curious instance of this ; for here neither cattle nor horses nor dogs have ever run wild, though they swarm southward and northward...
Стр. 220 - ... mandibles have lost their teeth, and have become mere nippers, deadly weapons indeed, but useless except in war. They have lost the greater part of their instincts : their art, that is, the power of building ; their domestic habits, for they take no...

Библиографические данные