REGENERATION OF ARMS IN BRITTLE-STAR. I / 



as determined by the direct action of the operation. It seems, on 

 the other hand, to be bound up with intricate reactions affecting 

 the whole character of the activities and organization of the ani- 

 mal. A more direct application of the above statements to the 

 special theories of regeneration would be out of place at the 

 present time. 



We may sum up my results on the rate of regeneration of the 

 arms of the brittle-star, Ophioglypha lacertosa^ as follows : 



1. There is a definite relation between the size (/. c., age (?) ) 

 of the animal and the rate of regeneration of its arms. The maxi- 

 mum rate is exhibited by individuals of medium size (with a disk 

 diameter of 12 to 15 mm.). Both the smaller and the larger ones 

 give a diminishing rate as we go away from this point. 



2. The greater the number of removed arms (excepting the 

 case where all are removed) the greater is the rate of regenera- 

 tion of each arm. 



HULL ZOOLOGICAL LABORATORY, 

 THE UNIVERSITY OF CHICAGO, 

 October 12, 1903. 



