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 



FIG. 22a 



FIG. 226 



FIG. 22c 



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 226) 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). 1 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- 



1 See paper ii, p. 89. 



