On the Origin of Species by Means of Natural Selection: Or, The Preservation of Favored Races in the Struggle for LifeJohn Murray, 1882 - 458 pagina's |
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Pagina vii
... bees - Slave - making ants - Hive - bee , its cell- making instinct- Changes of instinct and structure not necessarily simultaneous - Difficulties of the theory of the Natural Selection of instincts - Neuter or sterile insects Summary ...
... bees - Slave - making ants - Hive - bee , its cell- making instinct- Changes of instinct and structure not necessarily simultaneous - Difficulties of the theory of the Natural Selection of instincts - Neuter or sterile insects Summary ...
Pagina 57
... bees do not visit this flower . I have also found that the visits of bees are necessary for the fertilisation of some kinds of clover : for instance , 20 heads of Dutch clover ( Trifolium repens ) yielded 2,290 seeds , but 20 other ...
... bees do not visit this flower . I have also found that the visits of bees are necessary for the fertilisation of some kinds of clover : for instance , 20 heads of Dutch clover ( Trifolium repens ) yielded 2,290 seeds , but 20 other ...
Pagina 58
... bees more numerous than elsewhere , which I attribute to the num- ber of cats that destroy the mice . " Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine , through the ...
... bees more numerous than elsewhere , which I attribute to the num- ber of cats that destroy the mice . " Hence it is quite credible that the presence of a feline animal in large numbers in a district might determine , through the ...
Pagina 59
... bee is rapidly exterminating the small , stingless native bee . One species of char- lock has been known to supplant another species ; and so in other cases . We can dimly see why the competition should be most severe between allied ...
... bee is rapidly exterminating the small , stingless native bee . One species of char- lock has been known to supplant another species ; and so in other cases . We can dimly see why the competition should be most severe between allied ...
Pagina 74
... bees , nevertheless every female flower which I examined had been effectually fertilised by the bees , which had flown from tree to tree in search of nectar . But to return to our imaginary case : as soon as the plant had been rendered ...
... bees , nevertheless every female flower which I examined had been effectually fertilised by the bees , which had flown from tree to tree in search of nectar . But to return to our imaginary case : as soon as the plant had been rendered ...
Overige edities - Alles bekijken
The Origin of Species by Means of Natural Selection: Or, The ..., Volume 1 Charles Darwin Volledige weergave - 1889 |
The Origin of Species by Means of Natural Selection,: Or the Preservation of ... Charles Darwin Volledige weergave - 1891 |
The Origin of Species by Means of Natural Selection: Or, the ..., Volume 1 Charles Darwin Volledige weergave - 1898 |
Veelvoorkomende woorden en zinsdelen
adapted admit affinities allied species America analogous ancient appear Asa Gray beak become bees believe belonging birds breeds cause cells characters climate closely allied colour common progenitor continued crossed crustaceans degree developed difficulty distinct species doubt effects eggs embryo existing extinct extremely facts favourable fertilised fertility flowers formations formerly forms fossil Fritz Müller genera genus geological Glacial period gradations greater number groups of species habits Hence hybrids important individuals inhabitants inherited insects instance instincts intercrossing intermediate kind lamellæ larvæ less living male mammals manner Marsupials migration modified descendants natural selection naturalists nearly nest occasionally occur oceanic islands offspring organisation organs parent peculiar perfect pigeon pistil pollen present preserved principle probably produced quadrupeds ranked reciprocal crosses remarked resemblance rudimentary seeds sexual selection slight South America stamens sterility structure struggle successive supposed theory tion variability variations varieties vary whilst whole wings young
Populaire passages
Pagina 428 - In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation. Light will be thrown on the origin of man and his history.
Pagina 424 - Analogy would lead me one step further, namely, to the belief that all animals and plants have descended from some one prototype. But analogy may be a deceitful guide.
Pagina 322 - Every species has come into existence coincident both in space and time with a pre-existing closely allied species.
Pagina 23 - ... that which enables the agriculturist, not only to modify the character of his flock, but to change it altogether. It is the magician's wand, by means of which he may summon into life whatever form and mould he pleases.
Pagina 63 - If such do occur, can we doubt (remembering that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind? On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed.
Pagina 426 - ... when we regard every production of nature as one which has had a long history; when we contemplate every complex structure and instinct as the summing up of many contrivances, each useful to the possessor...
Pagina 50 - Two canine animals, in a time of dearth, may be truly said to struggle with each other which shall get food and live. But a plant on the edge of a desert is said to struggle for life against the drought, though more properly it should be said to be dependent on the moisture.
Pagina 3 - As many more individuals of each species are born than can possibly survive; and as, 'consequently, there is a frequently recurring struggle for existence, it follows that any being, if it vary however slightly in any manner profitable to itself, under the complex and sometimes varying conditions of life, will have a better chance of surviving, and thus be naturally selected.
Pagina 63 - Several writers have misapprehended or objected to the term Natural Selection, Some have even imagined that natural selection induces variability, whereas it' implies only the. preservation of such variations as arise and are beneficial to the being under its conditions of * life.
Pagina 388 - In my possession are two little embryos in spirit, whose names I have omitted to attach, and at present I am quite unable to say to what class they belong. They may be lizards or small birds, or very young mammalia, so complete is the similarity in the mode of formation of the head and trunk in these animals.