130 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



fairly normal but did not fuse until a greater 'distance from the base 

 than usual had been reached. The sclerenchymatous external lay- 

 ers, including the epidermis, showed less thickening, to which was due 

 the greater pliability of the etiolated stems. A few of the stalks of 

 the lower pinnae were elongated, but in every instance the foliar or 

 laminar tissues remained in a clump or bunch. 



Fig. 85. Onoclea sensibtlis. Partial transverse section of normal and etiolated 

 stipe. E. epidermis. 



Etiolation is thus seen to result in an excessive elongation of the 

 stipe in the basal portion. The rhizomes were not exhausted by the 

 growth of etiolated fronds, and appeared capable of making a second 

 effort to reach light. 



Ornithogallum umbellatum L. 



Bulbs of Ornithogallum placed in the dark chamber in January, 

 1901, developed leaves with a length of 22 cm. within a month. 

 The leaves were crescentic in cross section, many of them twisted 

 and about 6 mm. in breadth when flattened. The flower bud re- 

 mained dormant during the entire confinement to darkness, and when 

 the preparations were brought into light after two months, the leaves 

 showed some decay at the tips, but made an increasedjgrowth, while 

 the flower bud remained inactive. 



The bulbs were not exhausted by this treatment, and seemed 

 capable of making a second growth in darkness. 



