BAIN" (W THE EOOT CROPS. 155 



for example, growing on the edge of the turnip-field, is 

 the undoubted wild ancestor of the turnips themselves 

 the meadow navew. Its leaves are still rough and 

 hairy, so we can do little with them in the way of greens, 

 though when young and tender they are not unpleasant, 

 with their slightly bitter spinach flavor ; but its root is 

 larger and rounder than that of the charlock ; and here 

 the primitive husbandman shrewdly saw his practical 

 chance of an edible vegetable. By neglecting leaves or 

 seeds, and selecting the most favorable variations in the 

 root, he at last succeeded in producing a modified turnip, 

 from which later agriculturists have again developed the 

 still larger, coarser, and rounder swedes. Moreover, 

 though the seeds are but small and poor, they contain a 

 considerable proportion of oil ; and by concentrating 

 attention on this peculiarity, to the neglect of all others, 

 we have managed also to evolve independently from the 

 same parent stock another variety, the rape-seed, from 

 which we express colza oil. Each of these plants re- 

 mains exactly alike in foliage and flowers, because we 

 have expended no selective action upon those points ; 

 but in the parts on which selection has been infinitely 

 exercised they differ widely from one another, and from 

 the parent wild navew whose peculiarities already con- 

 tained them all potentially in the germ. To this day, 

 either turnips or beets which " break," as we call it 

 that is to say, which flower at the natural period 

 become small and shrunken ; because the original store 

 of food-stuffs was laid by in the root for the flowering 

 season ; and when the blossoms come out the plant has 

 practically reverted to its primitive condition. Similarly 

 with the cabbage : we have here adopted a closely 

 related variety one can hardly call it a species, the two 

 axe so much alike with smooth thickish foliage and a 



