94 BOTANICAL GAZETTE , [FEBRUARY 
small yellow knob, and the oldest having its sporangium full grown 
and turning black. They were all pointed in the direction of the 
afternoon light, making an angle of 135° with the incident electrical 
light rays. The five were watched closely from 8:15 to 9:55 P-M., 
the position of the tip of each being observed and recorded every 
5 min. During this time their development continued normally, 
the sporangia of the younger ones swelled, turned gray, and then 
nearly black, and the vesicular bulbs of all increased in size. In 
no one of the five was there any sign of bending toward the light, 
although they were watched for 1 hr. and 40 min. 
On the evening of May 21, 1910, observations were made on the 
reactions of three sporangiophores. The light was turned on at 
7:38. The sporangiophores were inclined away from the direction 
of the light at an angle of 125°. The sporangial swelling in all of 
them was yellow. The vesicular bulbs had not begun to form. At 
8:02 the sporangiophores had grown 1 mm. in length, but there 
was no change of position due to the presence of the light. The 
observation was continued until 9:20 p.m. The sporangiophores 
had not reacted toward the light, although they had continued 
their normal development. 
At 9:20 P.M., January 19, 1911, observations were begun on 
six sporangiophores. They were in the same field. The light was 
turned on at 7:20 P.M. and observations were made for 2 hrs. One 
of the sporangiophores stood vertically. It was slender tipped and 
showed no signs of sporangial swelling. At 7:50, after 30 min. 
_ exposure to the light, the tips showed a very slight curvature. The 
reaction then stopped and the tip began to swell slightly. When 
the light was turned off, the sporangial swelling was distinct. 
The remaining five sporangiophores at 7:20 stood at an angle 
of 135° to the incident light rays. All showed sporangial swelling, 
but the vesicular bulb had not started to form. There were no 
indications of response toward the light in any of them, although 
the sporangiophores continued their normal development through- 
out the experiment. At the close of the experiment the swelling 
of the vesicular bulb on all of them was just visible. Fig. 4 shows 
a sketch of these sporangia as they appeared at the beginning of 
the experiment. 
