CONTRIBUTIONS FROM THE BERMUDA BIOLOGICAL STATION 



FOR RESEARCH. — No. 15. 



REGENERATION IN THE BRITTLE-STAR OPHIOCOMA 

 PUMILA, WITH REFERENCE TO THE INFLUENCE 

 OF THE NERVOUS SYSTEM. 1 



By Sergius Morgulis. 



Presented by E. L. Mark, April 14, 1909. Received April 8, 1909. 



In animals with a well differentiated nervous system all functions 

 are so intimately associated with this system that the severing of the 

 connection between an organ and its nervous supply leads to a loss of 

 function, and at times also to an atrophy of the organ itself. Further- 

 more, the nervous system exercises an important role in regulating the 

 interrelation of parts of the organic complex, so that interference with, 

 or loss of, one function may — through the nervous system — lead to a 

 more or less profound disturbance of another function. Indeed cases 

 of abnormalities or monstrosities are not infrequently attributable to 

 some disturbance in the nervous system. 



Leaving aside entirely those instances which fall within the scope of 

 embryology, Herbst, it may be recalled, found in the crustacean Porcel- 

 lana that whether there was regenerated an eye or an antenna in place 

 of an extirpated eye depended wholly upon whether or not the optic gan- 

 glion had been injured by the operation. It may also be recalled that- 

 the exposure of the cut end of the nerve cord is a condition sine qua noti 

 for the regeneration of the head in the earthworm, as was discovered 

 by Morgan. 



The evidence concerning this problem of the influence of the ner- 

 vous system is, however, very conflicting in some important points, and 

 so far as vertebrates are concerned there is apparently no agreement 

 among writers, although the opinion is strong that the central nervous 



1 I am under obligation to Dr. E. L. Mark, both for the opportunity of 

 research which I enjoyed at Bermuda, and for the careful revision of the 

 manuscript. 



