HeredityJ. Murray, 1908 - 605 من الصفحات |
طبعات أخرى - عرض جميع المقتطفات
عبارات ومصطلحات مألوفة
abnormal acquired characters affect amphimixis ancestors animals biological body breeder cells centrosome changes chromatin chromosomes colour constitutional crossed cytoplasm Darwin determinants disease distinction dominant embryo environment Epenthesis evidence evolution experiments expression fact father female fertilised fertilised egg-cell fertilised ovum Galton's gametes germ germ-cells germ-plasm germinal variation Herbert Spencer hereditary heredity heritable hybrids hypothesis illustrate immune inborn inbred individual infection influence inheritance interpretation Karl Pearson larvæ latent male material Mendel's Mendelian Mendelian inheritance microbic modifications mother mutations natural selection normal nucleus number of chromosomes nurture nutrition occur offspring organism origin ovum pangenesis parents parthenogenetic particular peas peculiarities persistence phenomena physiological plants polar bodies possible predisposition prepotent produced Prof progeny pure race reappearance regard regression reproductive resemblance reversion seems species spermatozoon statistical structural suggested supposed T. H. Morgan telegony tendency theory tion transmission transmitted varieties Vries Weismann
مقاطع مشهورة
الصفحة 395 - Like leaves on trees the race of man is found, Now green in youth, now withering on the ground ; Another race the following spring supplies ; They fall successive, and successive rise : So generations in their course decay; So flourish these when those are pass'd away.
الصفحة 316 - It must be clearly understood that there is nothing in these statements to invalidate the general doctrine that the children of a gifted pair are much more likely to be gifted than the children of a mediocre pair. They merely express the fact that the ablest of all the children of a few gifted pairs is not likely to be as gifted as the ablest of all the children of a very great many mediocre pairs
الصفحة 316 - Mid-Parent, and still fewer would differ as widely as the more exceptional of the two Parents. The more bountifully the Parent is gifted by nature, the more rare will be his good fortune if he begets a son who is as richly endowed as himself, and still more so if he has a son who is endowed yet more largely.
الصفحة 415 - I have attempted to explain heredity by supposing that in each ontogeny, a part of the specific germ-plasm contained in the parent egg-cell is not used up in the construction of the body of the offspring, but is reserved unchanged for the formation of the germ-cells of the following generation.
الصفحة 412 - Through a great series of generations the germinal protoplasm retains its specific properties, dividing in every reproduction into an ontogenetic portion, out of which the individual is built up, and a phylogenetic portion which is reserved to form the reproductive material of the mature offspring. This reservation of the phylogenetic material I described as the continuity of the germ protoplasm." " Encapsuled in the ontogenetic material, the phylogenetic protoplasm is sheltered from external influences,...
الصفحة 3 - Since the issues of the individual life are in great part determined by what the living creature is or has to start with, in virtue of its hereditary relation...
الصفحة 119 - Is there evil but on earth? or pain in every peopled sphere? Well be grateful for the sounding watchword 'Evolution' here, Evolution ever climbing after some ideal good, And Reversion ever dragging Evolution in the mud.
الصفحة 128 - The father with a great excess of the character contributes sons with an excess, but a less excess of it ; the father with a great defect of the character contributes sons with a defect, but less defect of it. The general result is a sensible stability of type and variation from generation to generation.
الصفحة 376 - Permanent progress is a question of breeding rather than of pedagogics; a matter of gametes, not of training. As our knowledge of heredity clears and the mists of superstition are dispelled, there grows upon us with everincreasing and relentless force the conviction that the creature is not made but born.
الصفحة 508 - ... sciences. But if, as is usual, the philanthropist is seeking for some external application by which to ameliorate the course of descent, knowledge of Heredity cannot help him. The answer to his question is No, almost without qualification. We have no experience of any means by which transmission may be made to deviate from its course; nor from the moment of fertilisation can teaching, or hygiene, or exhortation pick out the particles of evil in that zygote, or put in one particle of good. From...