116 Dr. P. H. Carpenter on some Points in 



prove his tlieory incontestably. Has be performed this expe- 

 riment or any one which would give the same results? 

 Even then, however, his theory does not hold good for the 

 Stalked Crinoids, none of which have any radiating cavities 

 or pores at their syzygies, while these unions are altogether 

 absent in Bathycrinus. His assertion that water is expelled 

 from the coeliac canals of the arms through pores on the 

 " pourtour " of the syzygies would thus appear to be a some- 

 what hasty generalization from the supposed condition of the 

 Comatulce. It is essential, however, to his conception of a 

 Crinoid as a kind of sponge with incurrent and excurrent 

 openings for the circulation of water. The former are pro- 

 vided for by the ciliated water-pores on the disc ; but where 

 are the latter in IIolopus, Hyocrinus^ Bathycrinus, Rhizo- 

 crinus, and, I will also add, in the Pentacrinidge ? 



Professor Perrier's brief notice of the ' Challenger ' Report 

 contains the following passage *: — " Pousse par on ne sait 

 quelle prevention assez mal dissimulee contre ce qu'il appelle 

 un peu dedaigneusement ' I'^cole francaise,' M. Herbert 

 Carpenter, dont les etudes ont ete terminees a I'Universite de 

 Wiirtzbourg {sic), s'est,en bon camarade, jetetete baisseeala 

 suite du zoologiste allemand qui a le plus habilement etudie 

 les Crinoides. II affirm e en avoir confirme presque tous les 

 resultats dont beaucoup sont cependant errones, et il ne se 

 separe gubre de son guide que pour defendre les opinions, 

 d'ailleurs exactes, de son pere relativement au syst^me ner- 

 veux." 



The last sentence contains a statement which falls very 

 considerably short of the truth. Not only do I disagree with 

 the published views of my old friend Prof. Ludwig respecting 

 the nervous system of Crinoids, but I have given a different 

 account of the basals of RMzocrinus from that which he put 

 forward ; and, in common with Mr, Sladen t, I dissent alto- 

 gether from the theory which he has published concerning 

 the relations of the Crinoid calyx in the Urchins and Star- 

 fishes %. I differ from him and from other German writers, 

 Studer and Homes §, upon this purely theoretical point as 



* ' Revue Scientifique,' May 30, 1885, p. 693. 



t " On the Homologies of the primary Larval Plates in the Test of 

 Brachiate Echinoderms," Quart. Journ. Micr. Sci. n. s. vol. xxiv. 1884, 

 pp. 35-37. 



X Ibid. vol. XX. 1880, pp. 322-329 ; and " Notes on Echinoderm Mor- 

 phology. — No. V. On the Homologies of the Apical System, with 

 some Remarks upon the Blood-vessels," Ibid, vol. xxii. 1882, pp. 376- 

 386. 



§ " On the Apical System of Ophiurids," Ibid. vol. xxiv. 1884, pp. 15- 

 18 ; and Zool. Chall. Exp. part xxxii. pp. 392-400. 



