180 Roy a Society: — 



being filled up ; but the general truth of the deductions la none the 

 less lor such slight imperfections. If all is not, and cannot be, yet 

 known about transmutation of species, the great changes of climate, 

 the origin and metamorphism of rocks, and the antiquity of man, 

 yet the main outline of geological history has been fairly sketched 

 to the satisfaction of inquiring minds, and is suggestive of some 

 of the grandest ideas of which the mind of man is capable. 



PROCEEDINGS OP LEARNED SOCIETIES. 



ROYAL SOCIETY. 



April 6, 1876. — Dr. J. Dalton Hooker, C.B., President, in the 



Chair. 



Supplemental Note to a Paper "On the Structure, Physiology, 

 and Development of Antedon (Comatula, Lamk.) rosaceus.^' By 

 William B. Cakpextee, ;M.D., F.R.S. 



Since my communication of the above-cited Paper to the Royal 

 Society on the 16th December, 1875, two important contributions 

 to the Anatomy of Antedon have appeared — one by Dr. Ludwig, 

 chiefly based on his study of Antedon Eschrichtii (" Zur Anatomie 

 der Crinoiden," Zeitschiift fiir wissenschaftliche Zoologie, Bd. xxvi. 

 1876, p. 361, continued in Nachrichten von der Ktiuigl. Gresell- 

 schaft der Wissenschaften und der G. A. Universitat zu Grottingen, 

 No. 5, Feb. 23, 1876), and the other by Prof. Greef, of Marburg 

 (Sitzungsberichte der Gesellschaft zui' Beforderung der gesammten 

 Naturwissenschaften zu Marburg, January 1876), both of w^hich 

 seem to have been prompted by the appearance of Professor Sem- 

 per's short paper on the subject. These able observers fully concur 

 with me, as to all essential particulars, in the account I have given 

 of the triple canal-system of the arms, which M. Edmund Perrier 

 not only could not himself find, but ventured to predict that no 

 one else would find ; in fact. Professor Greef's figure of a trans- 

 verse section of an arm might have been copied from one of the 

 drawings I have had by me for more than ten years, save for one 

 slight additional feature. The German investigators also accept 

 the correctness of the statements made by me in my First Me- 

 moir, that the " nerve " of Miiller is really the genital rhachis, and 

 that Miiller's " A'essel " in the arms is soHd, not tubular — though 

 neither is disposed to believe with me that this " axial cord " is a 

 nerve. The character of a nerve, on the other hand, is assigned 

 by Ludwig to a fibrillar band lying beneath the epithelial floor of the 

 ventral furrow of the arms ; which band had been independently 



