1909] STREETER--DIRECTION OF GROWTH OF AMANITA 417 
stipe has ceased to elongate (fig. 5). In 24 hours after the toadstool 
had reached its maximum height, the pileus expanded and its diameter 
increased 1.2°™. In all cases where the plant was placed on its 
side after the stipe had reached its full length, but before the pileus 
Fic. 4.—A. phalloides, from which the pileus, except that part directly above the 
Stipe, has been removed. 
had fully opened, the pileus continued to expand; there was, however, 
no upward bend in the stipe (also shown in fig. 5). After the stipe 
attains its full length there is no longer any response to gravity 
stimulus. 
When a young plant, in which the entire stipe is still elongating, 
is placed on its side in the dark, the tip of the stipe begins to bend 
