520 A. MILNES MARSHALL. 



Finally, Dr. Carpenter has very recently^ given a summary 

 of the investigations concerning the nervous system of the 

 Crinoids which have been published since his former paper in 

 1876. He points out that the evidence accumulated in this 

 interval is most strongly in favour of his view, which, on the 

 other hand, is opposed merely " by a theoretical homology, a 

 preconceived notion of what Crinoids ought to be." He con- 

 cludes with some important observations on the morphological 

 aspects of the question, which will be noticed in a later section 

 of this paper. 



The present position of the question may be briefly described 

 thus. The Carpenters and Perrier, on the one hand, maintain 

 that the central capsule and axial cords, with their branches, 

 constitute the essential and principal part of the nervous sys- 

 tem, both motor and sensory, while the subepithelial bands, if 

 nervous at all, are of very subordinate functional importance. 

 On the other hand, Ludwig and the German morphologists 

 generally maintain that the subepithelial bands constitute the 

 sole nervous system. The former school cite in support of 

 their views a large mass of anatomical and histological obser- 

 vations and certain direct experiments ; while the latter school 

 rely entirely on theoretical morphological objections to the 

 views of their opponents. , 



III. Experimental Investigation of the Nervous System 

 OF Antedon rosaceus. 



This section of the paper, containing the account of my own 

 investigations made at Naples last April, I propose to sub- 

 divide under the following heads : — A. The movements of un- 

 injured specimens. B. The effects of removal of the visceral 

 mass. C. The power of regeneration. D. The functions of the 

 central capsule. E. The functions of the axial cords. F. The 

 functions of the subepithelial bands. 



1 Carpeuter, " On the Nervous System of the Crinoidea," ' Proceedings of 

 the Royal Society,' 1884. 



