ARTIFICIAL SELECTION 127 



feet the plant as a whole, or any j)art, with reference to size, 

 form, flavor, proportion of chemical constituents, time of 

 appearance or ripening, hardiness, and so on. Since in plants 

 which are raised from seed, the special peculiarities of the 

 parent are found to reappear in its offspring to a greater or 

 less degree, it becomes possible for the farmer to preserve in 

 future crops the peculiarities which please him, b}'^ taking 

 his seeds from those individual plants which satisfy him 

 best. Thus if early ripening is the quality desired, the earliest 

 seeds are the ones chosen year after year, until in the course 

 of several, or it may be many generations, furnishing earlier 

 and earlier plants, the offspring finally produced from these 

 selected seeds are found to ripen their product so much sooner 

 than any other sorts that they are recognized as a new 

 variety. 



With many plants, such as strawberries, the seedlings are 

 apt to vary so widely from the parent and from each other 

 that the varieties are said to. be "not true to seed": and in 

 these cases it is the practice w^hen once a seedling possessed 

 of desirable qualities has been obtained, to propagate it by 

 means of "cuttings" or similar detached portions of the 

 parent plant instead of by seed. 



Occasionally important differences appear among the in- 

 dividuals raised from cuttings or the like, and these may 

 similarly form the basis of new varieties. 



50. Artificial selection. Besides these principal ways in 

 which cultivated varieties arise, there are some others the 

 consideration of which must be deferred to a later chapter. 

 What at present concerns us is the general truth that to a 

 very large extent human or artificial selection exerts a control- 

 ling influence either upon the development or the perpetua- 

 tion of varieties, and frequently upon both. Since the longer 

 and more widespread the cultivation of a given plant has 

 been, the more extensive and more varied must have been 

 this influence, we should expect in general that the number of 

 varieties of a cultivated plant would be proportional to the 

 time and area of its cultivation; and this expectation we 

 find to be justified by the facts. 



