MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



157 



Potentilla sp. 

 Resting plants of a native species were brought in from the 

 meadows in the autumn, and after several months in a cool dry room 

 were placed in the dark chamber. The petioles developed a length 

 of 14 cm., the laminar portion of the leaf being represented by a 

 compact bud-like formation about 5 mm. long and 2 mm. thick. No 

 other organs were visible and the limited activity of the leaves was 

 coupled with a small supply of reserve material in the rootstocks. 



Pteris longifolia L. 

 Clumps of rootstocks of Pteris were placed in the dark room 

 early in March, 1901. In the succeeding cultural observations the 



Fig. 118. Culture of Pteris lot/gifolia with etiolated and normal leaves. 



fronds already formed persisted and appeared normal, the chlorophyl 

 retaining its usual aspect. Young fronds, sent up in the dark 



