The Study of Animal LifeScribner, 1892 - 375 páginas |
No interior do livro
Resultados 1-5 de 25
Página 49
... variations which were best adapted , and eliminating those which were conspicuous . But there are many instances of resemblance to sur- roundings which are hard to explain . Thus Dr. A. Seitz describes a restricted area of woodland in ...
... variations which were best adapted , and eliminating those which were conspicuous . But there are many instances of resemblance to sur- roundings which are hard to explain . Thus Dr. A. Seitz describes a restricted area of woodland in ...
Página 50
... variation due to the environment , and it is at least possible that the permanent whiteness of some northern animals ... variations . To several naturalists , but above all to Mr. Poulton , we are indebted for much precise information in ...
... variation due to the environment , and it is at least possible that the permanent whiteness of some northern animals ... variations . To several naturalists , but above all to Mr. Poulton , we are indebted for much precise information in ...
Página 51
... variation apart from the influence of the environment , that the power was fostered in the course of natural selection ... variations by natural selection . The question is whether the power arose in direct relation to environmental ...
... variation apart from the influence of the environment , that the power was fostered in the course of natural selection ... variations by natural selection . The question is whether the power arose in direct relation to environmental ...
Página 59
... variation , we can only speculate . To begin with , indeed , there must have been a general resemblance between the ... variations which are believed to be common among animals . It is logically possible that this may have been the case ...
... variation , we can only speculate . To begin with , indeed , there must have been a general resemblance between the ... variations which are believed to be common among animals . It is logically possible that this may have been the case ...
Página 92
... variations ; ( 2 ) that affection , co - operation , mutual helpfulness , sociality , have modified the struggle for material subsistence by lessening its intensity and by ennobling its character . ( b ) Kropotkine's Position ...
... variations ; ( 2 ) that affection , co - operation , mutual helpfulness , sociality , have modified the struggle for material subsistence by lessening its intensity and by ennobling its character . ( b ) Kropotkine's Position ...
Outras edições - Ver tudo
Palavras e frases frequentes
action active adult Amphibians ants backboned become begin Biology birds bivalves body brain buds called carbonic carbonic acid Chambers's Encyclop changes characteristic ciliated colony colour complex corals crab creatures crustaceans cuttlefish Darwin division of labour earth Echinoderms egg-cell eggs embryo Encyclopædia Encyclopædia Britannica energy Erasmus Darwin evolution Evolution of Sex fact female fertilised fishes food-canal freshwater frog function grow habit Haeckel heredity higher animals hydroid individual influence Infusorians insects instincts jellyfish kinds lancelet larvæ less living matter Lond male mammals mates medusoids molluscs Natural History natural selection naturalists nervous nest notochord observed offspring organism origin ovum parasites parents plants Prof progress Protists protoplasm Protozoa realised recognise regard reproductive cells reptiles result sea-anemones seems shells simplest animals skin sometimes species spermatozoa spiders sponges strange structure substances suggest surroundings theory tion tissues units variations Vertebrate worms young Zoea zoology
Passagens conhecidas
Página 339 - THERE was a child went forth every day, And the first object he look'd upon, that object he became, And that object became part of him for the day or a certain part of the day, Or for many years or stretching cycles of years.
Página 174 - I believe a leaf of grass is no less than the journey-work of the stars, And the pismire is equally perfect, and a grain of sand, and the egg of the wren, And the tree-toad is a...
Página 297 - Doing this, and making the requisite addition, the formula finally stands thus :—Evolution is an integration of matter and concomitant dissipation of motion; during which the matter passes from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity ; and during which the retained motion undergoes a parallel transformation.
Página 44 - When we reflect on this struggle, we may console ourselves with the full belief, that the war of nature is not incessant, that no fear is felt, that death is generally prompt, and that the vigorous, the healthy, and the happy survive and multiply.
Página 262 - It scarcely breathes with its one lung (the other shrivelled and abortive) ; it is passive to the sun and shade, and is cold or hot like a stone ; yet " it can outclimb the monkey, outswim the fish, outleap the zebra, outwrestle the athlete, and crush the tiger.
Página 289 - Fifthly, from their first rudiment, or primordium, to the termination of their lives, all animals undergo perpetual transformations, which are in part produced by their own exertions in consequence of their desires and aversions, of their pleasures and pains, or of irritations, or of associations; and many of these acquired forms or propensities are transmitted to their posterity.
Página 33 - I should premise that I use the term Struggle for Existence in a large and metaphorical sense, including dependence of one being on another, and including (which is more important) not only the life of the individual, but success in leaving progeny.
Página 24 - It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures.
Página 23 - Earth-worms, though in appearance a small and despicable link in the chain of Nature, yet, if lost, would make a lamentable chasm.
Página 289 - As air and water are supplied to animals in sufficient profusion, the three great objects of desire, which have changed the forms of many animals by their exertions to gratify them, are those of lust, hunger and security.