Oenothera Oblonga. 



343 



first two leaves, and at 5 a rosette two months old. These 

 are not mutants but plants grown from the seed of self- 

 fertilized oblonga. These cultures came quite true to 

 seed and exhibited a high degree of uniformity. The 

 first two leaves, after the cotyledonary ones, are broad 

 and with broad bases, markedly broader than those of 

 O. Lamarckiana at the corresponding age (Fig. 65 L, p. 

 326). This can be seen in Fig. 72> A and 5 at 1 and 2 

 as well as in Fig. 72. There soon follow narrower leaves 

 but the rate at which this decrease in breadth takes place 

 is not constant. Fig. 72) B is more typical in this respect 

 than the O. oblonga of Fig. 72, but the remaining seedlings 



Fig. yz- Seedlings of Oenothera oblonga. A, a few weeks 

 old, magnified (2.5/1). B, two months old, 'A natural 

 size, c, cotyledonary leaves. In B the leaves are marked 

 in the order in which they appeared. 



in the same box behaved essentially in the same manner. 

 I photographed many of them at the time, but do not 

 think it worth while to reproduce the others as well. 



As the plants grow their characters become more 

 pronounced, the leaves longer and narrower, the veins 

 broader, paler and more prominent. In the third month 

 growth takes place much faster, or at any rate produces 

 a more noticeable increase than in the first two. At the 

 end of that period the rosettes possess many leaves and 

 are very strong and ready for the development of the 

 stem (Fig. 74). If they do not do this they grow to a 



