[ 440 ] 



A Study of the Restitution Masses formed by the 

 Dissociated Cells of the Hydroids Antennularia 

 ramosa and A. antennina. 



By 

 W. De Morgan and the late Gr. Harold Drew, 



Beit Memorial Resem-ch FcHov:, 

 From the Laboratory of the Marine Biological Association at Plymouth. 



Figures 1-9 in the Text. 



TABLE OF CONTENTS. 



PAGE 



Litroduction ............. 440 



Methods and Technique ........... 443 



The normal tissues which, after dissociation, give rise to the restitution masses . 445 

 The process of formation of restitution masses ....... 448 



The morphology and duration of life of the restitution masses . . . .451 



The histology of the restitution masses ........ 453 



Synopsis of experiments . . . . . . . . . . .458 



Summary and conclusion .......... 462 



INTRODUCTION. 



The work described in this paper is, iii the main, a repetition of that 

 of H. V. Wilson, " On the Behaviour of the Dissociated Cells in Hydroids, 

 Alcyonaria, and Asterias," published in October, 1911, in the Journal 

 of Experimental Zoology. The results he obtained are so far-reaching 

 in their bearing on the present theories of the organization of living' 

 matter that his work appeared well worth repeating on species closely 

 allied to those on which he experimented. Our results largely bear out his 

 contentions, though we were not successful in carrying the regenerative 

 process as far as the production of new hydranths, and the histological 

 structure of the restitution masses we obtained differed in many ways 

 from that described in Wilson's paper. These differences are probably 

 due to the fact that we experimented with other species of Hydroids to 

 those used by Wilson : in other respects we have followed his technique 

 and repeated his experiments, and up to a certain point have obtained 

 the same results, and thus it may be considered that we have verified his 

 very remarkable work. 



