aa ee a EE 
1909] STREETER—-DIRECTION OF GROWTH OF AMANITA 425 
in three cases of stimulation for one minute, and in all cases (ten 
records) where the specimens were in a horizontal position only 30 
or I5 seconds, there was no direct upward curvature. Instead, the 
stipe had made a definite spiral curvature in the same direction as that 
in which the clinostat moved. Clinostats which rotated in opposite 
directions were used and the spiral always followed the direction of 
the clinostat (fig. 12). 
O find the latent period, the pileus was carefully removed that 
Curvature might not be retarded by the weight which would cause a 
Strain in an unusual place and the plants were placed in a horizontal 
position. Records were made every 
10 minutes. In young, vigorously 
growing specimens, there was an up- 
ward curvature observable in 4o 
minutes. In other specimens which 
were nearer maturity, the period was 
longer, in some cases being 60 minutes. 
Fic. 12 Fic. 13 
Fic. 12. A. phalloides: a, as placed on clinostat; 6, 24 hours later, showing 
Special curvature of stipe.—Fic. 13. A. phalloides, showing amount of curvature for 
€ach ro minutes for 80 minutes. 
No records which showed the downward bend were considered in this 
experiment. The diagram (jig. 73) shows the rate of curvature in a 
typical specimen. 
SUMMARY 
When young and vigorously growing toadstools were placed with 
the stipe in the horizontal position, the stipe of each toadstool bent 
and carried the pileus up to or beyond the horizontal position. This 
Supra-curvature when it occurred was neutralized if growth did not 
€€ase too soon. 
The responsive zone is situated near the tip of the stipe, not within 
the pileus. 
The stipe elongates throughout its entire length, until it is more 
