550 Mutations 



They came into existence at once, fully equipped, 

 without preparation or intermediate steps. No 

 series of generations, no selection, no struggle 

 for existence was needed. It was a sudden leap 

 into another type, a sport in the best acceptation 

 of the word. It fulfilled my hopes, and at once 

 gave proof of the possibility of the direct obser- 

 vation of the origin of species, and of the ex- 

 perimental control thereof. 



The third generation was in the main a repeti- 

 tion of the second. I tried some 10000 seed- 

 lings and found three lata and three nanella, or 

 nearly the same proportion as in the first in- 

 stance. But besides these a rubrinervis made 

 its appearance and flowered the following year. 

 This fact at once revealed the possibility that the 

 instability of lamarcklana might not be re- 

 stricted to the three new types now under obser- 

 vation. Hence the question arose how it would 

 be possible to obtain other types or to find them 

 if they were present. It was necessary to 

 have better methods of cultivation and examina- 

 tion of the young plants. Accordingly I de- 

 voted the three succeeding years to working on 

 this problem. 



I found that it was not at all necessary to 

 sow any larger quantities of seed, but that the 

 young plants must have room enough to develop 

 into full and free rosettes. Moreover I ob- 



