46 
PHYSIOLOGY: LOEB AND WASTENEYS 
result. It was found that for the polyps of Eudendrium the most 
efficient region of the spectrum was in the blue in the neighborhood of 
4735 angstrom units, which coincides with the region of maximal effici- 
ency found for the seedHngs of oats by Blaauw; while the region from 
4900 to 5300 and from 4690 to 4400 or below was still effective, but 
less than the region in the blue near 4735. The red and yellow rays 
were practically ineffective, at least an exposure of over 5 hours to the 
red and yellow rays induced no curvature. The following table may 
serve to illustrate this statement. 
The fact that in the first series (5 -minute exposure) one polyp bent 
to the light in the red was, as the other experiments showed, merely 
TIME 
WAVE- 
LENGTH 
COLOR 
POLYPS BENT 
TO THE 
LIGHT 
TIME 
WAVE- 
LENGTH 
COLOR 
POLYPS BENT 
TO THE 
LIGHT 
Angstroms 
Fraction 
Per 
cent 
Angstroms 
Fraction 
Per 
cent 
5 min. 
6500 A 
red 
1/29 
4 
15 min. 
6700-5400 
red to yellow- 
ish green 
0 
0 
6000 
yellow 
0/4 
0 
5400-4900 
yell o wish- 
green and 
green 
14/37 
38 
5700 
yellow 
0/13 
0 
4900-4100 
blue and 
violet 
72/95 
76 
5300-5345 
yellowish- 
green 
5/15 
33 
4100-3700 
violet 
14/30 
46 
5100 
green 
3/12 
25 
5| hrs. 
6560-6000 
red and 
orange 
0/32 
0 
4900 
blue 
11/32 
35 
5720 
yellow 
0/21 
0 
4735 
blue 
30/49 
62 
5500-5300 
green 
3/13 
24 
4690 
blue 
4/21 
19 
4950 
blue 
1/6 
16 
4600 
blue 
5/22 
23 
4800 
blue 
7/16 
44 
4400 
blue 
5/52 
10 
4700 
blue 
24/24 
100 
an accident. The region of maximal efficiency was in the blue of about 
4735 A. 
In the second series (15-minute exposure) no bending occurred in 
the red and yellow, in the green and bluish-green less than 50 percent 
bent to the light, in the blue 76 percent, and in the violet less than 
50 percent. 
The final series (5J-hour exposure) is given to illustrate the fact that 
even an exposure of 5 J hours does not induce any bending in the red 
and yellow, while in the blue in the region of 4700 all the polyps were 
bent to the light. It should be mentioned that this effect was already 
reached in the region of 4700 A. in 160 minutes; after an exposure of 
10 minutes already 73 percent were bent to the light. 
