76 On the Nervous System of the Crinoidea. [May 29, 



my deductions from them are unsound. To assert that they are 

 " evidently " erroneous, is clearly an unscientific mode of disposing 

 of them, unworthy of any real lover of truth. 



ADDENDA. 



(June 11.) I am permitted by Prof. A.M. Marshall, of Owens Col- 

 lege, to state that having, during a recent visit to Naples, repeated 

 for himself at Dr. Dohrn's Zoological Station the experiments which I 

 performed there in ]876 upon the Nervous System of Antedon rosacea, 

 he found their results confirmatory of my own in every particular ; 

 whilst be was farther led to assign an afferent as well as a motor 

 function to the dorsal nerve-system, as I had myself been led to do 

 by the absence of the ventral nerve in the aboral arms of Actinometrce. 

 Professor Marshall informs me that he hopes to publish an account 

 of his experiments in the next number of the Quarterly Journal of 

 Microscopical Science. 



(June 28.) I also learn from Prof. Marshall and my Son, that a 

 further experimental confirmation of my conclusions has been recently 

 published by Dr. Carl F. Jickeli of Jena.* Having investigated 

 the subject four years ago at Trieste, he not only repeated and 

 verified my experiments, but varied them by the use of electric 

 stimulation. He found that when this was applied to the ambu- 

 lacral groove of a detached arm, it produced no effect ; but that if 

 applied to the axial cord, it called the muscles of the arm and pin- 

 nules into contraction, so as to produce flexure, even though the arm 

 had previously shown no signs of life. If applied to the axial cord 

 of a cirrus, electrical stimulation threw the cirrus into tetanic con- 

 traction. Further, Dr. J. found that while the application of caustic 

 to the ambulacral groove of an arm had no effect in preventing the 

 excitation of flexure by electric stimulation of the axial cord, the appli- 

 cation of caustic to the axial cord itself caused a straightening of the 

 arm and a cessation of its movements, as if by the killing of its nerve. 



These results, says Dr. Jickeli, can be explained in no other mode 

 than Dr. Carpenter's ; and he further states that his histological 

 examination of the axial cord has satisfied him of its nervous character. 



In claiming to be the first, after my Son, who has publicly adopted 

 my view, Dr. J. seems unaware that Professor Perrier has been led 

 to accept it, by his study of the anatomical distribution of the pairs of 

 branches given off from the axial cord. (See note, p. 71.) 



W. B. C. 



The Society adjourned over the Whitsuntide Recess to Thursday, 

 June 19. 



tjber das Nerrcnsystem und die Sinnesorgane der Comatula Meditcrranea" in 

 " Zool. Anzeiger," 7 Jahrgang, No. 170, p. 346. 



