The Effects of Cross and Self Fertilisation in the Vegetable KingdomJohn Murray, 1876 - 482 pages |
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Common terms and phrases
anemophilous anthers average height average number bees capsules produced colour cross-fertilisation crossed and self-fertilised crossed flowers crossed plant flowered crossed seeds crossed with pollen Dianthus distinct plant entomophilous equal number Eschscholtzia fertilised plants fertilised with pollen fertility flower-stems four pots fresh stock Fritz Müller fully grown genera germinated grains greenhouse height as 100 hermaphrodite humble-bees inches in height insects intercrossed plants Ipomoea Ipomoea purpurea large number Lathyrus odoratus latter lots of seeds measured Mimulus Müller nectar Nicotiana number of capsules number of seeds offspring open ground opposite sides parent-plants Petunia plants growing plants in Pot plants produced plants raised plants self-fertilised pollen-grains Primula ratio of 100 Reseda odorata seedlings seedlings raised seeds per capsule self-fertilised capsules self-fertilised flowers self-fertilised in height self-fertilised plants self-fertilised seeds self-sterile sexual elements species spontaneously self-fertilised stamens sterile stigma superiority taller tallest crossed plants three pots tilised Total in inches visit the flowers whilst yielded seeds
Popular passages
Page 2 - As plants are adapted by such diversified and effective means for crossfertilization, it might have been inferred from this fact alone that they derived some great advantage from the process ; and it is the object of the present work to show the nature and importance of the benefits thus derived.
Page 417 - ... of distinct individuals of the same species ; but no one will suppose that insects act in this manner for the good of the plant. The cause probably lies in insects being thus enabled to work quicker ; they have just learnt how to stand in the best position on the flower, and how far and in what direction to insert their...
Page 27 - The most important conclusion at which I have arrived is that the mere act of crossing by itself does no good. The good depends on the individuals which are crossed differing slightly in constitution, owing to their progenitors having been subjected during several generations to slightly different conditions, or to what we call in our ignorance spontaneous variation.
Page 413 - That insects should visit the flowers of the same species as long as they can, is of great importance to the plant, as it favours the cross-fertilisation of distinct individuals of the same species ; but no one will suppose that insects act in this manner for the good of the plant.
Page 441 - There are two other important conclusions which'\ may be deduced from my observations : firstly, that the advantages of cross-fertilisation do not follow from some mysterious virtue in the mere union of two distinct individuals, but from such individuals having been subjected during previous generations to different conditions, or to their having varied in a manner commonly called spontaneous, so that in either case their sexual elements have been in some degree differentiated. And secondly, that...
Page 454 - ... with pollen from another individual or variety of the same species, they are fully fertile ; but if with pollen from a distinct species, they are sterile in all possible degrees, until utter sterility is reached. We thus' have a long series with absolute sterility at the two ends ; — at one end due to the sexual elements not having been sufficiently differentiated, and at the other end to their having been differentiated in too great a degree, of in some peculiar manner.
Page 437 - A fact of great importance in its bearing on the origin of varieties should be here noted. Any variation, arising as a so-called sport, in any group of plants where either of these...
Page 414 - Dictamnus fraxinella to a white variety ; from one to another very differently coloured variety of Delphinium consolida and of Primula veris ; from a dark purple to a bright yellow variety of Viola tricolor; and with two species of Papaver, from one variety to another which differed much in colour...
Page 267 - He says (loc. cit., p. 269): A cross between plants that have been self-fertilized during several successive generations and kept all the time under nearly uniform conditions does not benefit the offspring in the least, or only in a very slight degree. Mimulus and the descendants of Ipomoea named Hero offer instances of this rule. Again, plants self-fertilized during several generations profit only to a small extent by a cross with intercrossed plants of the same stock (as in the case of Dianthus)...
Page 51 - In this latter case the Colchester-crossed gave the lowest average of all ; and if these plants had been in any marked manner superior to the other two lots, as from my former experience...