MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



l6l 



the normal, and the lack of development of the stelar components 

 was fairly similar to that described in other oaks. The normal stem 

 has a subepidermal phellogen and a loosely arranged cortex con- 

 taining much chlorophyl. 



Quercus sp. 



Germinating acorns of an undetermined species of oak were 

 placed in the dark room in March, 1900. On May 19, cultures 

 in the dark room showed stems with 30 internodes and a height 

 of 75 cm., while the control plants in a room in which the tem- 

 perature was somewhat more fluctuating and the air was dryer, 



Fig. 120. Quercus sp. Transverse section of normal petiole. 



showed 8 internodes and a length of 22 cm. Etiolated leaves about 

 I cm. in length which was twice that of the stipules, were to 

 be seen, with a small lamina, which was not entirely unfolded. The 

 base of the etiolated stem had blackened and discolored up to a dis- 

 tance of 20 cm. from the base. A branch arose from the axil of the 

 sixth leaf, and reached a length of 20 cm., bearing only scale-like 

 leaves. The maximum length was shown by the fourth internode 



