202 Prof. C. Semper on the Anatomy of Comatula. 



XXV. — Brief Observations on the Anatomy of Comatula. By 

 C. Semper*. With an Addendum by W. B. Carpenter, 

 M.D., LL.D., F.K.S., &c. 



Since the publication of Miiller's celebrated treatise on the 

 structure of Pentacrinus caput-Medusaif, errors have been pro- 

 pagated by all the manuals of zoology (and so-called compara- 

 tive anatomy), the refutation of which no one, to my knowledge, 

 has hitherto attempted. To me, however, the erroneousness 

 of some individual statements of that great man was already 

 known while residing in the Philippine Islands ; and from 

 the commencement of my course as a teacher I have in my 

 lectures endeavoured to spread truer views. 



In the year 1868 I was intending to publish a short memoir 

 on that which I had found, when, becoming acquainted in 

 London with Dr. Carpenter, I was delighted to learn that that 

 able observer had obtained exactly the same results on Euro- 

 pean as I on Philippine Comatula?. In the expectation that the 

 English investigator would soon publish his already prepared 

 work on the Crinoidea, I deferred till now the communication 

 of the results of my examination : but since, after five years 

 waiting, there is imminent risk that from my lectures the re- 

 sults of Carpenter's and my own toilsome investigations may 

 somehow find their way into publicity, I hold that the moment 

 has arrived to break the silence I have hitherto kept. 



My present concern is only to correct Miiller's inaccurate 

 representation of the sexual parts and what he calls the nervous 

 system. He says (I. c. p. 57), " In the arms of Pentacrinus and 

 Comatula, between the joints and the membranous covering of 

 the groove (derived from the perisome), under the groove of 

 the tentacle are situated two J membranous canals, one above 

 the other. Between the two lies the nerve-cord of the arm, 

 specially enclosed in a membranous sheath ; opposite each 

 pinnule it forms a longish slight swelling from which the 

 nerve-fibre departs into the pinnule." This description has 

 been admitted into Gegenbaur's ' Grundziige der vergleich- 

 enden Anatomie,' 2nd ed. p. 321 §, and Claus's ' Zoologie,' 



* Translated from a separate impression, communicated by Dr. W. B. 

 Carpenter. 



t Abhandlungen der Berlin. Akad. 1841. 



j This is only partially correct. According to Miiller's own drawing 

 (I. c. pi. iv. f. 12), Alccto europaa lias only one canal in the arms ; the lower 

 one is absent. In the tropical Cvmatulce, however, it is present, and also 

 in the European, according to Edmund Perrier (Arch. d. Zool. Experim. 

 &c. tome ii. 18(33, pp. 49, 57). To the work of the latter I shall return 

 further on. 



§ I take this opportunity to protest against the mode in which Gegen- 



