Mutations 



55 



formed, around which is grouped a new series of fluctuating 

 variations, forming a frequency curve. (See Fig. 9.) 



5. In a fluctuating variation no new unit characters are 

 added. The same char- 

 acters are merely found 



in greater or less quan- 

 tity or number (Fig. 10) . 

 Where a mutation oc- 

 curs, new unit charac- 

 ters are added or old 

 ones lost. 



6. Fluctuating vari- 

 ations represent indi- 

 viduals or parts of them. 

 Mutations represent 

 groups of individuals. 



In fluctuating vari- 

 ations, the small differ- 

 ences are grouped 

 around what may be 

 called a " center of fluc- 

 tuation," which is the 



. FIG. 11. Chelidonium majus. 



mean of the frequency 



curve. When a mutation is formed, a new center of 



fluctuation is established around a new mean. 



History of mutation. The first mutation was recorded 

 in 1590. In the garden of Sprenger, an apothecary of 

 Heidelberg, was found a peculiar form of Chelidonium 

 majus. The new form appeared suddenly and without 

 intermediates from a lot of plants which had been culti- 

 vated for many years. This mutant had " leaves cut into 



