96 BOTANICAL GAZETTE [FEBRUARY 
The third sporangiophore was inclined at an angle of 80° from 
the incident light rays and measured 4mm. in length. It was 
slender tipped. Curvature was first visible at 7:58 and at 8:42 
was still very slight. At 8:50 there had been a slight increase in 
length, although no further change in direction was noted. Atg:40 
the curvature became more pronounced and at g:5o the tip was 
pointing almost directly toward the light. At this 
\\ \\ A\ time the curvature seemed to be arrested. No 
further observations were made on this sporangio- 
Fic. 7 phore (fig. 7). 
The fourth sporangiophore Saerved at the 
same time stood at an angle of 80° with the direction of the light. 
It was 2 mm. in length and the tip was slender and tapering. The 
reaction in this case was strikingly like that of the third sporangio- 
phore just described. They were very near together (fig. 8). 
The fifth sporangiophore measured 1 mm. in length at the 
beginning of the experiment. It was slender tipped 
and stood vertically from the surface of the culture. 
At 8:04 the tip had begun to curve. At 8:42 the \ \ \ 
tip had curved through an angle of 40°. At 9:13 Fic. 8 
it pointed in the direction of the light (fig. 9). 
Observations were begun on two sporangiophores on one 
culture at 7:40, January 21, 1911. They were slender tipped and 
made an angle of about 50° with the direction of the light. At 8:18 
both showed new growth which was curved slightly toward the 
light. The curvature continued with the growth until at 8:50 
the tip was directed straight toward 
(\ )\ the light. From that time until 
ay ea 9:50 when the observations were 
Fic. 9 concluded, the sporangiophores grew 
in the direction of the light (fig. 10). 
A group of five ca iachores was located in the field of the 
horizontal microscope at 8:40 P.M., November 2, 1911. The spo- 
rangiophores showed only slight differences in length and were 
inclined at an angle of 25° from the vertical. They were placed so 
that they leaned away from the light, making an angle of 95°. 
The sporangial swelling was just visible on the tips of all the spo- 
