MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



:o9 



dermal cells of the leaf were naturally smaller in the etiolated organs 

 and more regular in outline, while the palisade tissue, and spongy 

 parenchyma are not differentiated. 



Fig. 66. Partial cross section of etiolated stem of Galium circaezans. Descrip- 

 tion same as in Fig. 65, except that the cortex contains no chlorophyl. 



Gasteria disticha Haw. 



A single specimen brought into the dark room in September, 

 1900, soon began growth. The young leaves, the apices of which 

 were barely exposed, were carried into an erect position instead of 

 being brought to the horizontal as in the normal. A small offset 

 with thin linear or lanceolate leaves was developed from the basal inter- 

 node, reaching a length of several centimeters on May 20, (See Fig. 

 67.) This branch perished during the summer. Similar elongation, 

 and erection of propagative branches was to be noted in Sanseveria. 

 The main stem was greatly elongated, the internodes attaining a length 



