. Breeding of farm animals. Livestock. BASIS OF SELECTION—VARIATION 8l 4. Variations in pattern.—These have to do w^ith re- peated parts, such as extra teats on cattle and sw^ine, extra toes in cats and dogs, and the like. This group of variations is not common among animals, but evi- dences are everywhere observed among plants, as stool- ing of v^heat, oats, corn and the like. In selecting animals to improve definite qualities, the breeder should distinguish betw^een these four groups, as it w^ill give him a clearer idea of the nature of varia- tions and how to take advantage of them in his e
. Breeding of farm animals. Livestock. BASIS OF SELECTION—VARIATION 8l 4. Variations in pattern.—These have to do w^ith re- peated parts, such as extra teats on cattle and sw^ine, extra toes in cats and dogs, and the like. This group of variations is not common among animals, but evi- dences are everywhere observed among plants, as stool- ing of v^heat, oats, corn and the like. In selecting animals to improve definite qualities, the breeder should distinguish betw^een these four groups, as it w^ill give him a clearer idea of the nature of varia- tions and how to take advantage of them in his endeavor to improve animals for the service of man. Further, it is important to remember that each group may be of the non-inheritable sort, and thus affect the in- _,—_-, -«^i^^^ dividual only; or each may be inheritable, and thus influ- ence the herd or breed. Degrees of variations.— Animals are not only exceed- ingly variable, but there is great difference in the degree fig. 28-KAMBouiLLET k^™ -uhio which one individual devi- ^°^" . 1 A 1 Fins wool type ates from another. A clear understanding of this is necessary to gain an idea of the nature of variations, and hence to be able to take advan- tage of such deviations as do appear. Continuous variations.—Darwin supposed that varia- tions were by nature continuous, and that new forms originated by the gradual accumulation of very small differences through a long period of selection. Accord- ing to this theory if all of the individuals that ever lived could be so arranged as to bring nearest together those that are nearest alike, it would then be found that they would grade into one another by insensible differences. For a long time such was commonly assumed to be the case, and no doubt is true of much of the variation among our animals. This, of course, means that the breeder. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloratio
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectlivesto, bookyear1914
