NERVOUS SYSTEM OF ANTEDON ROSACEUS. 517 



in support of the nervous nature of the central capsule and 

 axial cords. 



Experiment B. — The visceral mass was removed from a 

 large and vigorous Antedon, leaving the calyx with the central 

 capsule and the arms intact. On replacing the animal in the 

 water it executed the usual swimming movements as 

 perfectly as the entire animal had previously done. 



Experiment C. — From a second active specimen, the entire 

 centrodorsal basin with its contents and appendages were 

 removed. On replacing the animal in the water all the arms 

 were rigidly straightened out, apparently by the action of 

 the elastic ligaments which the muscles were powerless to 

 antagonise. 



Experiment D. — In an active specimen the soft parts of 

 one of the arms were divided down to the calcareous segments. 

 On replacing the animal in water all the arms worked as 

 usual without the slightest disturbance of regularity. 



Experiment E. — By means of nitric acid applied with a 

 fine brush, the dorsal half of one of the arms was dissolved 

 away until the axial cord was reached and destroyed. On 

 replacing the animal in the water the inj ured arm remained 

 rigidly stretched out, while all the other arms worked 

 as usual. 



From these experiments Dr. Carpenter concludes that the 

 central capsule is the co ordinating centre of a nervous system 

 whose peripheral portion consists of the axial cords of the rays, 

 arms, and pinnules ; also that the subepithelial band, if a nerve 

 at all, has no immediate relation to the swimming movements 

 of the arms. 



In 1877 Ludwig^ published a more detailed account of the 

 subepithelial band in Antedon, in which he describes the band 

 and the columnar epithelium covering it as being sometimes 

 directly continuous with one another and sometimes separated 

 by a delicate horizontal lamella. This lamella he finds to be a 

 more constant and evident structure in Antedon Eschrichtii 



^ Ludwig, ' Morphologische Studien an Echinodermen,' Heft i, Abh. i; 

 ' Separat. Abdruck aus der Zeitschrift f. wisseuschaftliche Zoologie,' Bd. 28. 



