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THE AMERICAN NATURALIST [Vol. XLVII 



larger F 2 generation grown from the sister plant of the 

 same Class II, 11.35La, where 532 plants agreed in having 

 tliis same type of stem coloration characteristic of 

 grandiflora. 



The culture was remarkable for the length and breadth 

 of its leaves, which far surpassed that of the parents of 

 the cross and for its general vigor. In these respects 

 there was marked progressive evolution. The flower 

 size, however, was below the grand if ova type, the petals 

 ranging from 1.5 to 2.8 cm. long (those of grandi flora 

 being about 3.3 cm. long). Since none of these plants 

 appeared to present the possibility of developing the stem 

 coloration of Lamarckiana, I have not considered it worth 

 while to follow the family further. 



3. The Cross 11.35 m X a and its Reciprocal 11.35 

 a X m. — These crosses were made to determine whether 

 or not the peculiarity of the red glands with the other 

 correlated characters was in any sense or degree sex- 

 limited. Thus if these characters were carried by the 

 male gametes from the plant 11.35m, the progeny of the 

 cross 11.35 a X m should have the peculiarities of Class I, 

 while the progeny of the cross 11.35 m X a should have 

 the peculiarities of Class II. A behavior of this general 

 nature has been described by De Vries ('11) in his paper 

 on double reciprocal crosses. 



From the cross 11.35 m X a the contents of one capsule, 

 276 seeds, were sown. The culture, 12.45, gave 143 plants 

 which were brought to maturity. Of these, 50 plants pre- 

 sented the red-colored papilla? characteristic of 11.35m 

 and of the biennis parent, and 83 had the coloration of 

 11.35(1 and of the grandiflora parent. On the hypothesis 

 developed through the cultures previously described the 

 plant 11.35m should have the constitution Rr and the 

 plant 11.35a should have the constitution rr. The female 

 gametes of 11.35m should then have been of two sorts 

 {R and r), the male gametes from 11.35a should have been 

 all similar (r), and the plants of the culture distinguished 

 as oORr and 83rr. The expected ratio of the two classes 



