86 Negative Correlation in Oenothera Hybrids 



0. rubrinervis x rubricalyx, 0. rubricalyx x Lamarck iana and 0. La- 

 marckiana x rubricalyx. All of these were sown on the same day, 

 grown under the same conditions, potted, described and photographed 

 at approximately the same ages, and set into the field in adjacent rows 

 on the same day. Each of these families will be considered under a 

 separate heading. 



Oenothera rubricalyx Gates. 

 Pedigree No. 11410(1) x Self = 1231. 



Seeds sown January 30th, 1913, germinated in 16 20 days and 

 yielded 119 plants, which at 10 weeks of age were clearly divisible into 

 two groups in respect to morphological characters, and into two inde- 

 pendent groups in regard to the pigmentation of the leaves. These 

 four groups may be briefly characterized as (a) the rubrinervis-\ike 

 group, (b) the nanella-like group, (c) the spotted group, and (d) the 

 unspotted group. Two plants died unclassified. The remaining 117 

 were distributed as follows: (ac) 59, (ad) 48, (be) 8, (bd) 2. These 

 categories may be briefly characterized as follows: 



Plants of the (a) group containing 107 individuals, or 91 "45 per cent, 

 of the entire family, had rather lax, ascending rosettes of relatively 

 narrow leaves, resembling those of 0. rubrinervis, but in general a little 

 darker green and with more reddening of petioles and midribs in the 

 older leaves, the spotted sub-group (c) usually being a little more 

 strongly crinkled and a little more prominently dentate toward the 

 base of the blades than the unspotted sub-group (d), as seen in the 

 upper series of plants in Plate V. These may be compared with pure- 

 bred 0. rubrinervis-rosettes of similar age, which are shown in the lower 

 series on the same Plate. The adult plants all had the tall, wide-branching 

 form usually seen in vigorous strains of 0. rubrinervis, with the 

 characteristic long capsules of that species, but the buds were as in 

 the parent, relatively a little more slender than in my long-controlled 

 strains of 0. rubrinervis. 



In the following table, bud-measurements of these rubricalyx-plants 

 both red-stemmed (ac), and pale-stemmed (ad), may be compared with 

 corresponding measurements from four pure 0. rubrinervis-pedigrees 

 taken at about the same time (Aug. 1) and under similar conditions. 

 Each measurement entered in the table is an average from five buds 

 taken at random from five different plants in the indicated pedigree. All 



