^'*--] Setchell-Goodspeed-Clausen : Nicotiana Tahacum 475 



e. AuRicuLATA derivatives. The typical form of leaf is that of 

 type 10, illustrated in plate 72. The leaf blade of this form is char- 

 acterized by an abrupt contraction of the blade at the base, nearly, if 

 not quite, to the midrib. Clasping auricles, from which the name is 

 derived, are usually present in this form. 



/. Sessilifolia derivatives, of which the leaf of macrophylla may 

 be taken as the type. These derivatives are non-petiolate, as the name 

 indicates. 



a. Stenophylla derivatives 



Type 1, as may be seen from the drawing of Fo (cf. pi. 63), seems 

 very close to angiistifolia, and had light pink flowers. There were 25 

 plants of 12F3H.P-P4g, the leaves of which were carefully noted; but 

 one passed its flowering stage too early to be judged, so that the colors 

 of the flowers of 24 only are known. Sixteen plants had stenophylla 

 leaves very nearly of type 1, but the extent of the wing structure varied 

 somewliat. The remaining 9 had lanceolata leaves of type 14. In 

 flower color the segregation ratio noted was 5 red : 19 pink. No further 

 generations of this line were grown. 



Type 17 was not selected for illustration in Fo, but was a plant 

 very close to angustifolia. It had, however, somewhat narrower leaves 

 and deep pink flowers. The 25 plants of I2F3II4P3-P07 were uniform 

 and like the F^ parent except as to flower color ; 3 were red and 22 w^ere 

 deeper or lighter pink. This line was not grown through further 

 generations. 



Type 21, also, was not selected for illustration of the Fg plant, but 

 was chosen later for perpetuation because of its extremely close agree- 

 ment with angustifolia. The F3, I2F3H4P4P09, consisted of 25 vigorous 

 plants which seemed to be uniform to the finest detail and agreed in 

 every respect with plants of angustifolia. There were noticed in the 

 plants of this family peculiar fimbriae attached to the corolla, or split 

 corollas, or, in one instance, a split hose-in-hose flower such as occurs 

 at times also in pure angustifolia. This type seemed to be a pure 

 recombination of the characters of angustifolia. 



Type 21 was continued through to the seventh generation and 

 found to be constant in the uniformity of the individuals in the several 

 families. In 1913, 94 plants of F4 were grown ; in 1914, 85 plants of 

 F,,; in 1915, 10 plants of F^ ; and in 1916, 8 plants of F,. All these 

 populations closely resembled one another as to individuals as well 

 as those of the F3 and the F^ parent. They are all so close to angus- 



