THE SELF-FERTILIZATION OF PLANTS. 319 



dahlia," &c), " differ slightly from each other. The 

 whole organization seems to have become plastic and 

 tends to depart, in some small degree, from the 

 parental type." 



Each variety has some positive peculiarity, which is 

 wanting in all the other varieties of the same species, 

 and the absence of which, lessens the capacity of those 

 varieties, for reproduction. A plant, lacking many, and 

 important features will, as has been shown, have its re- 

 productive elements wholly incapacitated for union with 

 each other, or for union with the sexual elements of 

 other plants of exactly the same mould ; and yet, the 

 plant will be quite fertile, with other individuals of the 

 species, with forms dissimilar. The reason is; in the 

 former cases, the reproductive elements cannot build 

 a structure, when each lacks so many, and the same, 

 materials. In the latter case, they may build (though 

 each lacks many of the materials), if both make up, 

 with the forces of what characters they have, all, or 

 most, of what is needed. To be functionally perfect, an 

 organism must be, of the full structural integrity, of its 

 species. Man may mould the individuals, of a species, 

 into a multitude of shapes; but each such form (save 

 one), will, of necessity, be in derogation, both of its struc- 

 tural, and of its functional perfection. In such a way, 

 the whole organization may be shown to be "plastic;" 

 but, plastic, in much the same manner a man may be 

 shown to be, by cutting off his leg. May a truncated 

 crystal, with an edge lopped off, be rightly said to be 

 plastic ? Or, may a number of such truncated crystals, 

 be said to be plastic, merely because it is possible to 



