316 THE SELF-FERTILIZATION OE PLANTS. 



tionately developed. The evils which result to plants 

 from disproportionate development, are encouraged by 

 the process which planters have of " roguing " (i. e., 

 weeding out) those individuals, of a variety, which de- 

 part from the type prescribed by their owners. Dar- 

 win says (p. 34, Origin of Species) : 



" When a race of Plants is pretty well established, 

 the seed-raisers do not pick out the best plants, but 

 merely go over their seed-beds, and pull up the ' rogues,' 

 as they call the plants that deviate from the proper 

 standard." 



As this "proper standard," generally requires the 

 monstrous development of some one character only 

 (that character, which is valued); and suffers, or has 

 compelled, the reduction of other characters to a rudi- 

 mentary condition ; it is impossible for the plants, long 

 to continue their kind. To remain constant long, to a 

 a given type; either that type must approximate the 

 sum of all the positive characters of its species ; or it 

 must deviate from such "proper standard," by abating 

 the abnormally developed part; by increasing the de- 

 velopment of one or more of the other (i. e., the not 

 valued) parts; or by restoring some of the parts which 

 were wholly suppressed or rudimentary; or it must 

 supply some of these defects of structure by crossing 

 with individuals of another variety. 



So imperative is this alternative, of either extinction, 

 or change of form, where plants are defective in struc- 

 ture, that Darwin comments upon it, with some sur- 

 prise. The change of form is effected, generally, un- 

 consciously to man. For, those plants which persist 



