50 



DISCONTINUOUS VARIATION. 



interesting experiment of De Vries.* He sowed the 

 mixed seed of Chrysanthemum segetum obtained from 

 twenty different gardens. The topmost flowers of the 



8 







024 6 8 10 12 14 16 18 20 



Number of petals 



FIG. 15. Distribution of Petals in Primula officinalis. 



chief stem of each of the 97 healthy plants obtained 

 were examined, and were found to contain the follow- 

 ing numbers of ray florets: 



Ray florets, 12 13 14 15 16 17 18 19 20 21 22 

 Frequencies, 1 14 13 4 6 9 7 10 12 20 1 



*Arch. f. Entwickelungsmechanik, Bd. ii. p. 52, 1896. 



