144 



PLANT-BREEDING 



normal ones and these from the pollen of the monstrous in- 

 dividuals and saved and sowed their seed separately. The 

 seed of twisted origin produced 41 percent of abnormal stalks, 

 the control seed giving 37 to 44 per cent of twisted plants. 



Fig. 44. Twisted stems. A, Of a horsetail {Equisetum Telmateja). B. 

 of the wild teasel {Dipsacus sylveslris). 



Ribbon-Hke stems or fasciations are another hereditary 

 monstrosity. In such a race of the hawksbeard I isolated the 

 normal plants from the flattened stems and gathered the seed 

 separately. The first gave 20 per cent, the latter 20 to 40 per 



