Different colors would also appear in the flocks of fowls, because the birds of unusual colors would be protected and preserved, instead of being destroyed as they usually are in the wild state. Other peculiarities, too, such as large combs, crests, and feathered legs, would be developed in some lands and neglected in others. This is how it happened that after thousands of years in domestication the races of fowls in different parts of the world were quite different in size and form, but alike in being of many colors. From a species in this condition modern poultry breeders have made hundreds of distinct varieties. The easiest method of making a variety in domestication is to select specimens for breeding as near the desired type as possible, and to breed only from a few individuals in each generation which come nearest to the ideal type. In this way a variety that breeds quite true to the type may be established in from three or four to eight or ten years, according to the number of characters to be established as distinctive of the variety. Varieties are also made by crossing unlike individuals. This process is longer than the other, and sometimes requires a series of crosses to produce specimens approximating the ideal sought. After such specimens have been obtained the method is the same as in the first case. A variety is commonly considered to be well established when the greater part of the specimens produced are easily identified as of that variety. But no domestic variety is ever established in the sense that a species is. All are artificial, produced by compulsory separation and preserved only as long as it is continued. =Classification of domestic varieties of birds.= Domestic varieties of all kinds of live stock were at first mostly shape-varieties; that is, the individuals of a variety were alike in shape but of various colors. This is the case still with some varieties. These shape-varieties are mostly the common types of certain countries or districts. Thus the Leghorn fowl is the common fowl of Italy, and the Houdan is a type common in a small district in France. Such shape-varieties are called _breeds_. When other types were made by crossing such breeds they also were called breeds. When people first began to be interested in the improvement of live stock, the popular idea of a breed was that it was a domestic species, and there are still many people who hold this view. This popular misconception of the nature of a breed is responsible for much of the inconsistency and confusion in the ordinary classifications of domestic varieties. To it also is due the use of the term "variety" to apply especially to color-varieties, which are the principal divisions of breeds.