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acters adult animals blastodermic vesicle breed centrosome changes char chemical chro chromatin chromo chromosomal vesicles cleavage cells color blindness combinations contrasting characters crossed cytoplasm daughter determined Diagram differential cause Drosophila ectoderm egg and sperm egg cell embryo endoderm environment environmental evidence evolution experience extrinsic fact factors of development female fertilized egg formed functions Galton gametes gastrula genes genotypes germ cells germinal germplasm give rise heredity human hybrid individual kinds known male maturation Mendel Mendelian Mendelian inheritance ment mind mitosis modified mutations normal nucleus number of chromosomes offspring oosperm organism pairs Paramecium parents peas peculiarities phenomena physiological plants polar bodies possible present principles probably produced protoplasm pure dominants pure recessive race ratio reflexes responses result seeds segregation sex cells showing shown species sperm spermatogonia spermatozoa spindle stages stimuli structures substances tion types usually variations wrinkled X chromosomes yellow zygote
Page 71 - Great wits are sure to madness near allied; And thin partitions do their bounds divide: Else why should he, with wealth and honour blest, Refuse his age the needful hours of rest?
Page 341 - He hath put down the mighty from their seats, And hath exalted them of low degree. He hath filled the hungry with good things ; And the rich he hath sent empty away.
Page 211 - An organic being is a microcosm — a little universe, formed of a host of self-propagating organisms, inconceivably minute and numerous as the stars in heaven.
Page 216 - ... as testifying that the power of judging aright and of distinguishing Truth from Error, which is properly what is called Good Sense or Reason, is by nature equal in all men; and that the diversity of our opinions, consequently, does not arise from some being endowed with a larger share of Reason than others, but solely from this, that we conduct our thoughts along different ways, and do not fix our attention on the same objects.
Page 65 - All peculiarities which are characteristic of a race, species, genus, order, class and phylum are of course" inherited, otherwise there would be no constant characteristics of these groups and no possibility of classifying organisms. The chief characters of every living thing are unalterably fixed by heredity. Men do not gather grapes of thorns nor figs of thistles. Every living thing produces offspring after its own kind. Men, horses, cattle ; birds, reptiles, fishes; insects, mollusks, worms; polyps,...
Page 298 - We greatly want a brief word to express the science of improving stock, which is by no means confined to questions of judicious mating, but which, especially in the case of man, takes cognisance of all influences that tend in however remote a degree to give to the more suitable races or strains of blood a better chance of prevailing speedily over the less suitable than they otherwise would have had.
Page 285 - ... whether the course of Evolution can at all reasonably be represented as an unpacking of an original complex which contained within itself the whole range of diversity which living things present.
Page 77 - The Law of Ancestral Inheritance which he stated as follows: The two parents contribute between them on the average onehalf of each inherited faculty, each of them contributing onequarter of it. The four grandparents contribute between them one-quarter, or each of them one-sixteenth; and so on, the sum of the series 1/2 + 1/4 + 1/8 + 1/16 . . . being equal to i, as it should be.
Page 200 - ... at the time of fertilization the hereditary potencies of the two germ cells are not equal, all the early stages of development, including the polarity, symmetry, type of cleavage, and the pattern, or relative positions and proportions of future organs, being foreshadowed in the cytoplasm of the egg cell, while only the differentiations of later development are influenced by the sperm. In short the egg cytoplasm fixes the general type of development and the sperm and egg nuclei supply only the...