144 



STUDIES IN GENERAL PHYSIOLOGY 



my specimens of Sertulariae. 

 "In place of normal individuals, 

 stolons were formed." 1 I have 

 observed these abnormalities, 

 however, in Gonothyrsea Lovenii, 

 which I grew in poorly aerated 

 aquaria. 



HETEROMORPHOSIS IN GONO- 

 THYR^IA LOVENII 



Stems of Gonothyrsea Lovenii, 

 which were cut off close to the 

 root and fixed vertically in the 

 sand with the tip downward, 

 formed new tips at their upper 

 basal ends, so that biapical stems 

 resulted (Fig. 23). 



The influence of contact 

 stimuli upon the longitudinal 

 growth of the roots was very 

 marked. Roots that were 

 brought in contact with 

 the surface of solid bodies 

 grew many times faster 

 than roots growing in the 

 middle of the aquarium 

 without any such contact. 



DRIESCH, " Heliotropismus bei Hydroidpolypen," Zoologische Jahrbiicher, 

 nerausgegeben von SPENGEL, Vol. V, p. 150. 



