1909] 



DE VRIES— TRIPLE HYBRIDS 



5 



flowered. All of them were velutina. In 190 



/ 



nated 



laeta and some velutina and got 80 and 45 seedlings respectively. 

 The first were all laeta, the second lot was uniformly velutina. Of 



specimens 



tie time of flc 

 intermediate 



In 



them 



them 



under the same conditions for comparison. The lata from the 

 strigosa cross had narrower leaves but with the rounded tips; the 

 bracts were broad but less bent downward. The flowers were much 

 smaller than those of the mother, but somewhat larger than those 

 of the father. Their shape resembled that of 0. strigosa, but the 

 stigma showed, although in a lessened degree, the peculiar hand- 

 shaped form of the ordinary O. lata. The anthers touched the 

 stigma, but only with their lower halves. The flower buds were 

 broad, and the tube was relatively short. In all these points and in 

 the other characters the lata hybrids were strikingly intermediate 

 between the two parents. Even the bent tips of the young leaves 

 were to be seen, and at once revealed the father. But the most 

 interesting feature was that of the pollen. O. lata is purely female, 

 while O. strigosa has the ordinary supply of pollen. The hybrids 

 showed some pollen and a relatively small number of fertile grains. 

 These were, during ordinary weather, insufficient for fertilization, 

 even if the pollen of many flowers was brought upon one stigma. 

 But there were individual fluctuations, and so I succeeded in getting 

 self- fertilized fruits on at least one specimen. 



Oenothera lata X O. biennis Chicago.— This cross was made in 

 1905, both parents being annual. Two 



used. 



specimens 



three 



years and had the following results : 



6 



Y 



ear 



Number of 

 specimens 



Percentage laeta 



27 



34 

 36 



35 



Percentage 



velutina 



Percentage lata 



70 

 29 

 28 



34 



3 

 37 

 35 



3i 



