No. 561] GENETIC AL STUDIES ON JEN OTHER A 551 



papillae). I lay no stress on the fact that in my small 

 cultures the numbers were 8622 : 80r, hut merely wish to 

 note the point that in this F 2 generation two classes ap- 

 peared sharply distinguished by the presence or absence 

 of the character under discussion. 



I was unable to differentiate in this F 2 other characters 

 on the plants 11.35m and 11.35a associated with the pres- 

 ence or absence of the red papilla? (see Davis, '12a, p. 

 395). There was a wide variation in habit, leaf, form, 

 inflorescence, flower proportions and flower size (petals 

 2.2-3.9 cm. long), a variation that seemed unrelated to the 

 presence or absence of red papillae. In this culture also 

 appeared a group of 15 dwarfs, recognizable when young 

 rosettes, which at maturity were from 5-6 dm. high, 

 sparsely branched, and with a foliage of narrow leaves; 

 6 of these dwarfs had the stem coloration of the biennis 

 parent (red papillae) and 9 that of grandiflora. 



Among the plants with red papillae on the stems I 

 selected an individual. 12.4:5//. which among my hybrids 

 with the stem coloration of Lanmrck'nutu most resembled 

 that form. I shall make this plant the starting point of 

 a pure line with the hope that in later generations I may 

 find variants still closer to the Lamarckiana type which 

 may be isolated by selection. Whether the plant is homo- 

 zygous with respect to the red coloration of the papillate 

 glands is a point to be determined by the next generation. 



2. The F 2 Generation from 11.35a.— From this plant 

 with the stem coloration of the grandifiora parent (pa- 

 pillae green over green portions of the stem), the contents 

 of one capsule, 432 seeds, were sown. The culture. 12.42, 

 produced 165 seedlings of which 147 plants were brought 

 to maturity. These presented uniformly the stem colora- 

 ion of the F t hybrid plant 11.35a and of the grandifiora 

 parent. It seems then safe to conclude that such a plant 

 as 11.35a is homozygous as to its stem coloration with 

 possibly the formula of a recessive (rr) lacking the factor 

 that produces the red color in the papillate glands. This 

 position is supported by the evidence from the much 



