Of course, we are all familiar with this “congenital or innate variation,” as shown by brothers and sisters in human families. How and why do innate variations arise? They arise from chemical and mechanical action upon the “germs” or reproductive cells contained in the body of the parents, and also sometimes from the mating in reproduction of two strains or races which are already different from one another. When an animal or plant is given unaccustomed food or brought up in new surroundings (as, for instance, in captivity) its germs are affected, and they produce variations in the next generation more abundantly. The best analogy for what occurs is that of a “shaking up” or disturbance of the particles of the germ or reproductive material, somewhat as the beads and bits of glass in a kaleidoscope are shaken and change from one well-balanced arrangement to another. And the same analogy applies to the crossing or fertilising of “strain” or “race” by another differing from it. A disturbance is the consequence, and a departure in the form and character of the young from anything arrived at before often takes place. These variations have no necessary fitness or correspondence to the changed conditions which have produced them. They are, so to speak, departures in all and every direction--not very great, but still great enough to be selected by survival if occurring in wild extra-human nature, and obvious enough when produced in cultivated animals and plants to be seen and selected by man, the stock-breeder or fancier. Indeed the stock-breeder and horticulturist go to work in this way deliberately. Though when they have fattened an animal or fed up a plant they cannot make it transmit its fatness or increased size to its offspring, yet they can, by special feeding and change of conditions of life--or by cross-breeding--break up the fixed tendency or quality of the germs within the parents so treated. Thus they get offspring produced which show strange and unexpected variations of many kinds--new feathers, new colours, new shapes of leaf, increased size of root, length of limb--all kinds of variations. From the congenital varieties thus produced by “stirring up,” “breaking down,” or disturbing the germ-matter (germ-plasm) of the parents, the breeder next proceeds to select and mate those which show the character which suits his fancy, whilst he destroys or rejects the others. Thus he establishes, and by repeated selection in every generation maintains, and if he desires increases, the characteristics which he values.