526 Mutations 



of the wild locality, and in the garden. A third 

 and last method of getting still more new spe- 

 cies from the original strain, was the repetition 

 of the sowing process, by saving and sowing 

 the seed which ripened on the introduced 

 plants. These various methods have led to the 

 discovery of over a dozen new types, never pre- 

 viously observed or described. ^ 

 -^ Leaving the physiological side of the rela- 

 tions of these new forms for the next lecture, 

 it would be profitable to give a short descrip- 

 tion of the several novelties. To this end they 

 maj^ be combined under five different heads, ac- 

 cording to their systematic value. The first 

 head includes those which are evidently to be 

 considered as varieties, in the narrower sense 

 of the word, as previously given. The second 

 and third heads indicate the real progressive 

 elementary species, first those which are as 

 strong as the parent-species, and secondly a 

 group of weaker types, apparently not destined 

 to be successful. Under the fourth head I shall 

 include some inconstant forms, and under the 

 last head those that are organically incomplete. 

 Of varieties with a negative attribute, or real 

 retrograde varieties, I have found three, all of 

 them in a flowering condition in the field. I 

 have given them the names of laevifolia, hrevi- 

 stylis and nanella. 



