198 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



normal length, soon becoming curved as in normal mature organs, 

 but did not assume the irregular corkscrew form of these or- 

 gans. Etiolated tendrils were irrita- 

 ble to contact in the stage when they 

 had reached a maximum size, but the 

 resulting curvatures carried the tips 

 through only a few degrees, except 

 with continued contact, and in a few 

 instance these organs succeeded in 

 encircling a support. If the irritable 

 surface was placed in contact with a 

 support one or two turns would be 

 made around it, but the free portion 

 did not assume the corkscrew form. 

 If stems which had begun growth in 

 light were removed to the dark room 

 the first etiolated tendrils developed 

 subsequent to the removal were larger 

 than if the entire growth had taken 

 place in the dark room, affording an- 

 other example of the endurance of the 

 stimulating effects of light in partial 

 etiolations. 



The excessive thickness of etio- 

 lated stems was found to be due to the 

 greater size, and perhaps some multi- 

 plication, of the parenchymatous ele- 

 ments in the stele and cortex. The 

 tips of the stems as well as the petioles were apogeotropic. 



Fig. 154. Entire etiolated shoots 

 of Ibervillea Sonorae. B, B, sup- 

 port, clasped bj' a tendril at A. 



Lycopodium lucidulum Michx. 

 A number of bulblets of Lycopodmm hicidtdum in the germinat- 

 ing stage were found near Cold Spring Harbor, L. I., about the 

 middle of July, 1902, and representatives of the various stages of 

 development were preserved, while some in a resting condition were 

 brought in and placed in the dark chamber. These structures are 

 composed of several thickened fleshy leaves, and are formed in the 

 axils of stem leaves, being in fact modified branches, and containing 

 much chlorophyl. About a month after confinement in the dark 



