The Breeding of Animals
Macmillan, 1917 - 310 頁
The cell. Reproduction. The Breeding season. Gestation and lactation. Fertility. Sterility. Heredity. Inheritance of acquired characters. Heredity and sex. Variation. In-breeding. Cross-breeding. Development. The practice of breeding.
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acquired American amount appearance Association average become believed birth body bred breeder breeding bull cattle cause cell cent changes characters closely continued cross desirable determined disease division domestic animals effect environment evidence examples existence Experiment fact feed female fertility five foals followed four function Gain germ-cells germ-plasm gestation given groups growth heat heredity horns horse hybrid important improvement in-breeding increase individual influence inheritance known larger later less litter live male mare mating mature ment method milk Missouri months mother mule nature normal observed offspring organs parent period pigs plants Plate possess possible pounds practical pregnant present probably produced pure qualities ration record relation reported reproductive result selection sexual sheep similar sire sows species stallion Station sterility successful supply tion transmitted true uterus valuable variation weight young
第 168 頁 - Their colour is bay, marked more or less like the quagga in a darker tint. Both are distinguished by the dark line along the ridge of the back, the dark stripes across the fore-hand, and the dark bars across the back part of the legs.
第 152 頁 - Salvator had four children; they were two boys, a girl, and another boy; the first two boys and the girl were six-fingered and six-toed like their grandfather; the fourth boy had only five fingers and five toes. George had only four children; there were two girls with six fingers and six toes; there was one girl with six fingers and five toes on the right side, and five fingers and five toes on the left side, so that she was half and half. The last, a boy, had five fingers and five toes.
第 219 頁 - That any evil directly follows from the closest inter-breeding has been denied by many persons ; but rarely by any practical breeder ; and never, as far as I know, by one who has largely bred animals which propagate their kind quickly.
第 1 頁 - It is to the cell that the study of every bodily function sooner or later drives us.
第 133 頁 - Understood in its entirety, the law is that each plant or animal produces others of like kind with itself : the likeness of kind consisting not so much in the repetition of individual traits as in the assumption of the same general structure.
第 104 頁 - The formation of milk is intimately connected with the reproductive powers. The secretion of milk is dependent upon the activity of the mammary glands; and these are either under the direct influence of the breeding organs, or else they sympathize very closely with them. Those animals which breed with the least difficulty, yield the best supplies of milk, and produce the most healthy and vigorous offspring.
第 225 頁 - This same observer also relates that a well-known breeder bred a family of pigs in-and-in for seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and when attempting to move could not walk straight...
第 222 頁 - My herd of cattle has, therefore, been bred in-and-in, as it is termed, for upwards of eighty years, and by far the greater part of it in a direct line, on both sides, from one cow now in calf for the twentieth time. I have bred three calves from her, by two of her sons, one of which is now the largest cow...
第 166 頁 - Agassiz believed in telegony. He was strongly of opinion • that the act of fecundation is not an act which is limited in its effect, but that it is an act which affects the whole system, the sexual system especially; and in the sexual system the ovary to be impregnated hereafter is so modified by the first act that later impregnations do not efface that first impression.
第 151 頁 - Btate of nature. Almost every part of every organic being is so beautifully related to its complex conditions of life that it seems as improbable that any part should have been suddenly produced perfect, as that a complex machine should have been invented by man in a perfect state.