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THE AMERICAN NATURALIST [Vol. XLIX 



were only two in the F 3 of 1913) proved to be of very 

 different genetic constitution. The progeny of one, num- 

 bering 100 plants, were all strictly like the parent, show- 

 ing not the slightest deviation from f. typica. The other 

 progeny, however, repeated the diversity of the F 3 gen- 

 eration, containing five plants of f. typica, 13 of mut. 

 semialta and five of mut. debilis in a culture of 24 plants. 

 This progeny, also, included one plant of a third dwarf 



mutation, which will be referred to below as mut. bilonga. 



The two F 3 plants of mut. semialta which were used as 

 parents gave very similar progenies, consisting of mut. 

 semialta and mut. debilis. In one case the numbers were 

 41 of mut. semialta and five of mut. debilis in a total of 

 46; in the other case, 83 of semialta and four of mut. 

 debilis in a total of 87. 



