28 Mutual Independence of Hereditary Characters 



grown through a few generations in thousands of speci- 

 mens, one can almost always observe that hardly any two 

 are alike. Some revert to the form of the pollen-parent, 

 others to that of the pistil-parent ; a third group occupies 

 a central position. Between these are placed the others 

 in the most motley variety of staminate and pistillate 

 characteristics and in almost every gradation of mutual 

 inter-mixture. 



Many and prominent authors have pointed out the 

 significance of hybrids for establishing the nature of fer- 

 tilization. With the same right we may use them in try- 

 ing to penetrate into the mystery of specific character. 

 And then they clearly prove to us that this character is 

 fundamentally not an indivisible entity. The character- 

 istics of a hybrid (of the first generation) are as sharply 

 defined and as constant, and on the whole of the same 

 order as those of the pure species, and the frequent spe- 

 cific name, hybridus, might go to prove that even the 

 best systematists felt this agreement. 

 N Kolreuter, Gartner, and others have combined in one 

 hybrid two, three, and more species, and there is no rea- 

 son why any other than a purely practical limit should 

 be put to this number, and that, in fact, there should not 

 be combined in one hybrid characteristics which have 

 been taken from an unlimited series of allied species. 

 But this is of small importance, the chief point being the 

 proposition that the character of a pure species like that 

 of hybrids, is of a compound nature. 



Crossings of varieties of the same species belong, es- 

 pecially in horticultural practice, to the most common 

 operations. Ordinarily the object pursued is simply that 

 of producing intermediate forms. Not infrequently, 



14 E. g. Papaver hybridum L., Trifolium hybridum L. 



