G14 P. HERBERT CARPENTER. 



propose eventually to describe the comparative anatomy of this 

 portion of the vascular system in the various types of Crinoids. 

 At present, I would emphasise two points strongly, viz. the 

 connection of the central plexus with the oral ring and genital 

 vessels above, and with the vascular axis of the stem at its 

 other end, which does not communicate with the exterior, as 

 the corresponding (?) part of the ovoid gland is said to do in 

 the Echinozoa. 



It will be evident from what has been written above that, so 

 far as the vascular system is concerned, I am inclined to adopt 

 Ludwig's views rather than those held by Professor Perrier 

 and his colleagues. The French author, however, is returning 

 good for evil, and sides with me in one, if not both, of the two 

 cardinal points wherein I disagree with Ludwig, viz. the 

 nervous system of the Crinoids, and the homologues of their 

 basal plates in Starfishes. It is with the first of these questions 

 only that I am now concerned. For the past six years I have 

 been continually advocating my father's view respecting the 

 nervous nature of the fibrillar envelope of the chambered organ 

 of the Crinoids, and its extensions into the rays and arras. 

 Ludwig, however, expressed his total dissent from this doctrine; 

 and it has consequently been ignored or dismissed with the 

 briefest possible mention in the various German text-books on 

 comparative anatomy. I have reason to believe that a few 

 teachers have assented to it; but, so far as I know. Professor 

 Perrier is the first continental worker on Echinoderms who has 

 publicly adopted it. This is the more important, as he for- 

 merly expressed his inability to do so ; and he has been able 

 to strengthen it in two important points. For he has not only 

 seen the ultimate branches of the axial cords, which altogether 

 escaped the notice of the German observers, but he has also 

 traced a connection between some of them and the muscle- 

 fibres through the intervention of stellate cells ; while he has 

 followed others into the tentacles, and describes them as enter- 

 ing the papillse borne by these organs. I have lately found 

 that these ramifications of the axial cord occur in the stem of 

 Pentucrinus and Bathycrinus, and that they are greatly 



