204 



GENERAL BOTANY 



The new forms thus produced by mutation are constant small 

 species, or " elementary species," termed mutants. If these new 

 plants can be recognized and selected, and the seeds sown in 



isolated breeding plots, it is pos- 

 sible to secure a new constant 

 strain at once without further 

 selection. In reporting upon the 

 work of the Swedish station De 

 Vries says: 



Besides wheat, the cultures of 

 oats, peas, and vetches are seen to 

 produce sports from time to time at 

 Svalof. Here also the sports are 

 sudden and without preparation or 

 intermediates, each of them at once 

 constituting a new type, which is 

 as distinct from its allies as any 

 new form found in the fields. 



FIG. 113. Variation in timothy 



The two lower plants grew side by side from the same seed. Desirable type at the 



right ; dwarf plant at the left. Dwarf plant with large spikes in the upper figure. 



Photograph by New York Agricultural Experiment Station 



