426 BOTANICAL GAZETTE [DECEMBER 
than half grown. The zone of most rapid elongation is always just 
below the pileus and becomes shorter and shorter until growth ceases. 
When placed in the horizontal position, the tip of the stipe curved 
upward very slowly at first, then more rapidly, until it passed the 
vertical position, after which the curvature took place more slowly 
until it came to rest. If growth were still vigorous, the tip of the 
stipe again passed the vertical, rested on the other side, and finally 
assumed the ordinary position. 
The amount of time which a toadstool must be stimulated in order 
that reaction may follow is less than a minute. How much less was 
not satisfactorily determined, probably because the clinostats used 
rotated too slowly. : 
The latent period varied from 40 to 60 minutes, the younger specl- 
mens responding more quickly. 
Jersry City, N. J. 
