142 STUDIES IN GENERAL PHYSIOLOGY 
had been in contact with the lead plate. These roots attached 
themselves to the lead plates and spread over their surfaces. 
I have not yet succeeded in producing bibasal Eudendria. 
VIII. HETEROMORPHOSIS IN SERTULARIA (POLYZONIAS ?) 
Heteromorphosis can be produced in Sertularia; but just 
as the heteromorphoses in no two of the animals thus far 
s 
FIG. 22a FIG, 22b FIG. 22¢ 
considered are exactly similar in every detail, heteromor- 
phosis in Sertularia has its specific characteristics also. I 
cut off stems of Sertularia close to the root and fixed them 
in an inverted position in the sand. Both roots and stems 
(Figs. 22a and 22b) grew from the cut basal end. But 
while the stems grew upward (and in the direction of the 
rays of light), the roots grew downward (and away from the 
source of light).’ As shown in my earlier observations, the 
roots of Sertularia are negatively, the branches positively, 
heliotropic. Biapical stems can be easily produced in the 
manner described. Not uncommonly the condition repre- 
sented in Fig. 22c¢ is found, in which a negatively helio- 
1See paper ii, p. 89. 
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