428 STUDIES IN GENERAL PHYSIOLOGY 
iu Eudendrium racemosum more closely in Woods Hole. 
The results of these observations are briefly reported in the 
following pages. 
II. NEW EXPERIMENTS 
1. The species of Eudendrium studied in Woods Hole 
has the same name as that in Naples—namely, Eudendrium 
racemosum; it is, however, not certain that the two forms 
are identical. The following statements hold for the form 
in Woods Hole. When fresh stems of Eudendrium are put 
into an aquarium, all the polyps soon fall off, probably due 
to unavoidable injury in collecting and handling the mate- 
rial. In the course of a few days, however, with a good 
supply of oxygen and a sufficiently high temperature, new 
polyps are developed. It was the dependence of this new 
development on light which was studied. 
A large quantity of vigorous colonies was collected each 
time. Long stems were picked and put in separate vessels, 
ten being distributed into each vessel, all of which contained 
an equal quantity of sea-water. Each of the stems usually 
formed from ten to twenty polyps. The different vessels 
were exposed to various kinds of light. In each experiment 
I therefore dealt, not with the development of a single 
polyp, but with a large number of them. I thought it 
necessary, furthermore, to make another set of control ex- 
periments by exposing the same stems successively to differ- 
ent kinds of light. 
Experiment 1.—On August 8 a number of stems of the 
same culture of Eudendrium was divided as equally as pos- 
sible between two vessels, in the manner described above. 
One of the vessels was exposed to diffuse daylight; the other 
was placed in a dark box which was ventilated every even- 
ing. The supply of oxygen was the same in the light as in 
the dark, and the temperature was always the same in the 
two vessels. 
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