NOTES ON ECHINODEHM MORPHOLOGY. 371 



Notes on Echinoderm Morphology, No. V.^ On the Homo- 

 logies of the Apical System, with mme Remarks upon the 

 Blood-vessels. By P. Herbert Carpenter, M. A., Assist- 

 ant Master at Eton College. 



DuEiNG the last two years the morphology of the Echino- 

 derms has engaged the attention of several continental natura- 

 lists. Some of their observations tend to support views which I 

 have advanced in the pages of this Journal, while others are 

 directly opposed to them. Under the latter head come the re- 

 searches of the French school into the anatomical relations of 

 the vascular system ; and it is curious that the conclusions to 

 which Messrs. Jourdain, Koehler, Apostolides, Perrier, and 

 Poirier have been led differ in toto from those of the German 

 school as represented by Greeff, Hoffmann, Lange, Simroth, 

 Teuscher, and especially by Ludwig. These last have been 

 sufficiently described in a previous number of this Journal (vol. 

 xxi). It is hardly time as yet to give a resume of the observa- 

 tions of the Erench school, but one or two of their principal 

 conclusions may be briefly alluded to. 



Both Perrier and Apostolides have published figures of their 

 preparations, the former having worked at the Urchins, and the 

 latter at the Ophiurids ; but neither Jourdain nor Koehler have 

 as yet given more than brief abstracts of their results,^ while the 

 complete memoir of Messrs. Perrier and Poirier on the anatomy 

 of the Asterids is not yet in print. All these observers, how- 

 ever, agree in one important point. The so-called "heart" or 

 *' central plexus " of an Urchin, Starfish, or Ophiurid is not a 



' Under this title I propose to continue from time to time the series of 

 papers bearing on this subject, which I have already published in previous 

 volumes of this Journal, e.g. : 



I. — 'On the Oral and Apical Systems of the Echinoderms,' part 1, vol. 

 xviii, 1878, p. 351. XL— The same, part 2, vol. xix, 1879, p. 176. 

 III. — ' Some Disputed Points in Echinoderm Morphology,' vol. xx, 1880, 

 p, 321. IV. — 'The Minute Anatomy of the Brachiate Echinoderms,' 

 vol. xxi, 1881, p. 169. 



2 'Comptes Eendus,' t. Ixv, pp. 1002-1004; t. xciii, pp. 651-653; 

 t. xciv, pp. 139-141, and pp. 744-746; t. xcv, pp. 459-461. See also 

 Perrier and Poirier, in t. xciv, pp. 658-660, and pp. 891, 893. 

 vol. XXII. NEW SER. i^ 13 



