No. 579] 



MUTATION EN MASSE 



133 



striking, and leaves no room for doubt as to the proper 

 classification of any individual. Fig. 3 shows adjacent 

 plants of mut. debilis and mut. semialta; Fig. 4 mut. 

 debilis and f. typica. Figs. 5, 6 and 7 show branches of 

 the three forms, on the same scale of reduction. 



The F 4 generation, grown in 1914, consisted of the 

 progenies of two plants of each of the three types. The 

 two externally identical parent plants of f. typica (there 



