580 Wisconsin Academy of Sciences, Arts, and Letters. 
solutely the intensity of the two lights used, the object being to 
determine th© relative effect of the colors with varying intensity 
due to distance. 
When the culture was two centimeters from the blue glass 
and 36 centimeters from the white, 88.6 per icent of the spo- 
ranges were thrown toward the blue, 11.4 per cent toward the 
white. When the culture was eight centimeters from the blue 
and 30 centimeters from the white, 14.8% and 25% were found 
on the two glasses respectively. At 12 centimeters from the 
blue and 26 centimeters from th© white, 52.8% struck the blue 
glass and 47.1% the white, the numbers now being almost equal 
although the culture is still less than half as far from the blue 
glass as from the white. When the culture was at 18 centi¬ 
meters from the blue and 20 centimeters from the white, only 
30% struck the blue and 70% the white. At 28 centimeters 
from the blue and ten centimeters from the white, all th©. spo¬ 
ranges were fired toward the white end. -Table XIII contains 
the data in complete form. It is seen that in no case, even 
when the ratio was 2 to 36 in favor of the blue, were all the 
sporanges discharged toward the blue. The curve in Figure 17 
is plotted from these data. The percentages of sporanges fired 
toward one of the two glasses are used as abscissas and the dis¬ 
tances from the culture as ordinates. The area above the curve 
indicates the proportion which struck the white glass and the 
area below, that which struck the blue glass. Although the 
Table XIII_ Blue glass and white glass at opposite ends of the box. Cul¬ 
ture moved 2 cm, each day from 2 cm. from the blue glass to 2 cm. from 
the white glass. Opening 2 cm. in diameter. 
Distance from blue. 
2 cm. 
4 cm. 
6 cm. 
8 cm. 
10 cm. 
12 cm. 
14 cm. 
16 cm. 
18 cm. 
Number on blue. 
101 
50 
95 
218 
20 
101 
237 
25 
10 
Per cent on blue. 
88.6 
89.2 
90.49 
74.82 
71.42 
52.87 
62 
37.92 
30.3 
Distance from white.... 
36 cm. 
34 cm. 
32 cm. 
30 cm. 
28 cm. 
26 cm. 
24 cm. 
22 cm. 
20 cm. 
Number on white. 
13 
6 
10 
5 
8 
90 
135 
36 
23 
Per cent on white. 
11.4 
10.8 
9.52 
25.17 
28.57 
47.12 
38 
62.07 
69.69 
Distance from blue. 
20 cm. 
22 cm. 
24 cm. 
26 cm. 
28 cm. 
30 cm. 
32 cm. 
34 cm. 
36 cm. 
Number on blue. 
3 
2 
1 
11 
0 
13 
0 
1 
0 
Per cent on blue. 
1.61 
5.88 
3.03 
5.55 
0 
4.58 
0 
.96+ 
0 
Distance from white.... 
18 cm. 
16 cm. 
14 cm. 
12 cm. 
10 cm. 
8 cm. 
6 cm. 
4 cm. 
2 cm. 
Number on white. 
183 
32 
32 
75 
142 
231 
222 
142 
190 
Per cent on white. 
98.38 
94.11 
96.96 
94.44 
100 
95.41 
100 
99.03 
100 
