Genetical Studies on Oenothefa. V. 201 



when ins(!ct pollinated developed capsules with seeds in abundance. 

 Tliis shows that the self-sterility was not due to abnormalities in the 

 ovules but must be concerned eithei' with the male g-ametes or with a 

 failure on the part of the pollen tubes to reach the embryo sacs. 



A brief description will now be given of the plants in the recip- 

 rocal crosses considered above, 12'12 gigas X muricataW, and 12"13 

 muricata W X gigas. The 4 exceptional plants in these cultures will 

 be treated separately. 

 Mature rosettes. Leaves broadly spatulate (Fig. 19), soniewliat crinkled in oliler rosettes 



clearly a blend of parental characters. A slightly darker shade of green in 12'12 



than in 12'13 and consequently somewhat patroclinous in color. 

 Mature plants. About 1'5 m. high, somewhat taller in 12'13; long branches from the 



base of the plants (Fig. 20). In habit intermediate between the parents. 

 Foliage. Leaves similar in both crosses, crinkled, broader than those of muricata, but 



longer than those of gigas (Figs. 20, 21). In form closely intermediate between 



the parents. 

 Infiorcseence. Bracts ^!^ — V.i length of mature buds, lanceolate, broad at the base 



(Fig. 21). Inflorescence in both cultures resembling more closely the (/«(/as parent 



but with clear evidence of muricata. influence. 

 Matui-e buds. About 7 cm. long. Cone stout, 4-angIed (Fig. 21). Sepals green or with 



faint reddish streaks. Sepal tips relatively short and thick. In both form and 



size the buds are closely intermediate between the parents. 

 Petals. 2"2 — 2"4 cm. long. In size somewhat below a mean between the parents and 



therefore inclining towards muricata. 

 Stigma lobes. Slightly below the tips of the anthers thus resembling muricata. 

 Capsules. Developed when open pollinated. In form intermediate between the parents 



but smaller than the mean. 



There remain for consideration 4 exceptional plants present in 

 cultures 12-12 and 12-1.3. The first of these, 12-12 ma, was evidently 

 a dwarfed form differing from its 10 sister plants chiefly in reduced 

 vigor. This plant is shown in Fig. 20 at the left of the type repre- 

 sentative of the cross. It was a shorter plant, sparsely branched, and 

 with reduced foliage, but the inflorescence, buds, and flowers presented 

 the characters of the culture as a whole. The cross 12-12, gigas X 

 muricata W, could not then be said to show more than one type of 

 hybrid. Somewhat different was the situation in culture 12-13, 

 muricata W X gigas. Among the 40 rosettes of this cross 3 plants 

 were early distinguished by their very narrow leaves, which in the 

 mature rosettes (Fig. 22) were similar in form to those of muricata. 

 The mature plants, 1 — rs m. high, were shorter than the sister plants 

 constituting the mass of the culture, and sparsely branched. In 1 plant, 

 12-13 ma, the foliage continued to be narrow-leaved, but the other 2 

 plants outgrew this condition of their rosettes and developed a broad- 



Induktive Abst.immungs- und Vererbniif^slcitre. XII. 14 



