Every one admires the luxuriance of garden-flowers, and their diversity of color and form. All parts of the world have contributed to their number and every taste can find its preference among them. New forms produced by the skill of the breeder are introduced every year. This has been done mostly by crossing and intermingling the characters of introduced species of the same genus. In some of the cases the history of our flowers is so old that their hybrid origin is forgotten, as in the case of the pansies. Hybridizations are still going on in other groups on a large scale, and new forms are openly claimed to be of hybrid origin. Breeders and amateurs generally have more interest in the results than in the way in which they have been brought about. Excellent flowers and fruit recommend themselves and there seems to be no reason for inquiring [122] about their origin. In some cases the name of the originator may be so widely known that it adds weight to the value of the new form, and therefore may advantageously be coupled with it. The origin and history of the greater part of our garden-flowers, fruits and vegetables are obscure; we see them as they are, and do not know from whence they came. The original habitat for a whole genus or for a species at large, may be known, but questions as to the origin of the single forms, of which it is built up, ordinarily remain unanswered. For these reasons we are restricted in most cases to the comparison of the forms before us. This comparison has led to the general use of the term "variety" in opposition to "species." The larger groups of forms, which are known to have been introduced as such are called species. All forms which by their characters belong to such a species are designated as varieties, irrespective of their systematic relation to the form, considered as the ancestor of the group. Hence, we distinguish between "hybrid varieties" and "pure varieties" according to their origin from different parents or from a single line of ancestors. Moreover, in both groups the forms may be propagated by seeds, or in the vegetative way by buds, by grafting or [123] by cutting, and this leads to the distinction of "seed-varieties" and "vegetative varieties." In the first case the inheritance of the special characters through the seeds decides the status of the variety, in the latter case this point is left wholly out of consideration.