 -Ior4] JOLIVETTE—PILOBOLUS 103 
The sporangia, however, are not discharged in equal numbers 
toward the two openings. In the extreme case all might go to one 
or the other of the openings. It happened that in only one case 
(experiment 7, table I) did this occur, and then the total number 
was 22, the number being small and affording less chance for 
variation than would a larger number. The entire data thus 
show a great diversity of results as regards the number fired toward 
either opening. It is significant that the element of chance enters 
strongly into these results. 
The fact that the sporangia do fire toward one or the other 
opening and in any degree of variation suggests further that 
although a large number of sporangiophores arise from one myce- 
lium, they are not gregarious as regards physiological response 
toward light stimuli, that is, they act as separate individuals 
toward a light stimulus. 
A further set of experiments was arranged to determine whether 
the sporangia to the right of the culture are discharged toward the 
right opening and those to the left of the culture to the left opening. 
With the apparatus arranged as before, a second series of experi- 
ments was made with a thin plate of glass placed with its edge 
vertical to the middle line of the exposed surface of the culture. 
This glass would then intercept the sporangia discharged from the 
left side of the culture to the right opening and vice versa. 
In the first experiment 2 sporangia struck each of the two 
openings, the number of sporangia in the consecutive 1-cm. areas 
to the left of the left opening are 8, 6, and 1; 3 sporangia were 
found on the 1-cm. area to the right of the opening. The first, 
second, and third 1-cm. areas to the left of the right opening con- 
tained respectively 1, 2, and 1 sporangia. The glass placed verti- 
cally at right angles to the surface of the culture received 7 sporangia 
on the left side and 15 on the right. The distribution of those on 
the left was as follows: 4 in the rst cm. toward the culture, 2 in the 
4th cm., and 1 in the 7th. The distribution of the sporangia on 
the right-hand side of the glass shows 7, 5, and 3 in the first 3 cm. 
These data, together with those of the second and third experi- 
ments made in this series, are found in table II. These experi- 
ments tend to show that some of the sporangia on the right side of 
