MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



137 



Oxalis lasiandra Zucc. 

 Bulbs of Oxalis lasiandra placed in the dark chamber at various 

 times were compared with cultures in very diffuse light, and in day- 

 light. The first activity was shown in the development of leaves with 

 elongated petioles and some offsets. The roots did not break out un- 



A B 



Fig. 94. Oxalis lasiafidra. Transverse sections of leaf. A, normal; B, etiolated. 



til later. The length of the petioles was as much as 11 or 12 times 

 that of the normal in some examples, while in others it might not 

 reach more than double the length of the normal. In one series of 



Fig. 95. Oxalis lasiandra. Surface view of epidermis of leaf. A, normal; B, 

 etiolated. 



tests the average length of normal petioles was 20.87 cm., in diffuse 

 light 36.9 cm., and in darkness 47.1. The thickness in normal and 



