1915] BARTLETT—MASS MUTATION 447 
G. 10.—Mut. albicans: 6 rosettes of the F, progeny of f. typica, from F, parent 
ss sansa E-5; the right-hand plant in the middle row, Lexington E-5-190, 
will be found in fig. 2; the two plants in the lower row, E-5-191 (left) and 195 (right), 
will be found respectively in figs. 3 and 
