MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



123 



A second series of cultures with a species native to eastern 

 America in March in the dark chamber showed a development of 

 two leaves with a length of 23 and 25 cm. which were free only a 

 few centimeters at the tip. The slightest exposure to the light used 

 in examination was sufficient to stimulate the production of chloro- 

 phyl. 



Lysimachia terrestris (L.) B.S.P. 



Lysimachia terrestris consists of a branching rhizome with aerial 

 leafy stems which may bear flowers, or the numerous branches may be 

 converted into, or remain in the form of, bulbils as the author has 

 discovered in some previous investigations. When such rhizomes 



D 



Fig. 79. Lysimachia terrestris. Partial transverse section of normal stem. A, 

 ^ir-spaces iu cortex; B^ xylem ; C, bast fibers; Z>, glandular ducts; E, sieve tissue. 



are placed in the dark room, slender etiolated stems without branches 

 or bulbils are produced, with internodes of a length of i to 5 cm., 

 while in the normal stem the length of the internodes varies from 

 5 cm. to 3 cm., the longest being found in the middle of the stem 

 below the flower-bearing branches. The total length of the etiolated 

 stem was slightl}^ greater than that of the normal flowering shoot, 



