UNIVERSITY OF CALIFORNIA PUBLICATIONS 



IN 



ZOOLOGY 



Vol. 6, No. 10, pp. 205-221 August 23, 1910 



CONTRIBl'TIONS PROM THE LABORATORY 



OF THE 



MARINE BIOLOGICAL ASSOCIATION OF SAN DIEGO. 

 XXX. 



BIOLOGICAL STUDIES ON CORYMORPHA. 



III.— REGENERATION OP HYDRANTH AND 

 HOLDFAST 



BY 



HARRY BEAL TORREY. 



In the second study of this series 1 the normal development of 

 C. palma was considered and its extraordinary plasticity pointed 

 out. I shall now give an account of the differentiation of 

 hydranth and holdfast after section of the column, both in the 

 larva and the adult, and make comparisons with corresponding 

 processes in the egg development. 



I. REGENERATION IN THE ADULT. 

 1. Development of the Hydraxth. 

 The regeneration of a hydranth on a stem of Corymorpha 

 from which the original hydranth has been removed by a simple 

 transverse cut, is ordinarily accomplished by a transformation of 

 the stem, as in Tubularia, but by a process which differs in some 

 details from the process of the latter. The wound closes within 

 a period varying widely between a lew hours and several days. 

 Immediately after section, the vacuolated cells composing the 

 supporting axial tissue of the column swell out in the shape of 

 a low dome, and the body wall soon begins to advance over them. 



i II. The Development of C. palma from the Egg. Univ. Calif. Publ. 

 Zool., 3, p. 253, 1907. 



