53 

 3. Notes on the Clitellum of the Earthworm. 



A criticism. 

 By W. Blaxland Benham, D.Sc. (Loud.) Hon.M.A. (Oxon.), Aldrichian Demon- 

 strator in Comparative Anatomy, Oxford. 



eingeg. 30. December 1S93. 



A paper was read on June 8th 1892, before the »Edinburgh Uni- 

 versity Darwinian Society« by Mr. Frank J. Cole, Assistant in the 

 Zoological Department of the (Edinb.) University, upon the j)Physio- 

 logy of the clitellum in L. terreatrisv.. The paper was printed and publi- 

 shed and owing to the courtesy of the author I received a copy of it. 

 Had it not been republished (with but slight alterations as to his «ideas« 

 on copulation and cocoon formation) in the »Zoologischer Anzeiger« 

 No. 434, 435, it might well have been passed over without notice: but 

 in its present form it Avill be widely distributed and may be read by 

 numerous zoologists who are not acquainted with the recent literature 

 on this subject, and since it is full of errors of observation and misconcep- 

 tions and ignorance as to the theories of earlier writers, it appears to 

 me, as one who has been engaged for the last six years on the special 

 study of the Oligochaeta, to be desirable to draAv attention to the paper, 

 lest the statements therein be accepted as accurate. 



Mr. Cole, who now dates his paper from the »Physiological Labo- 

 ratory of the University of Oxford« discusses the structure and function 

 of the Clitellum, and the process of Copulation in the Earthworm. 

 With the exception of the usual textbooks, his acquiantance with 

 the literature of the subject does not include that of the last five and 

 twenty years ; for while quoting the classic paper on the histology of the 

 Earthworm by Claparède in 1869, and one on the anatomy, by 

 Lankester 1865, he makes no reference to the standard works of 

 Vejdovsky, nor the careful and accurate account of the structure 

 of the clitellum given by Cerfontaine in 1890^: Even if he had 

 known of the existence of these and other memoirs on the subject, it 

 is probable that he would still have published his paper : as he would 

 have disagreed with all their statements. 



For although it is perfectly easy, by means of any ordinary elemen- 

 tary histological method (such as hardening in alcohol and staining 

 in Borax Carmine) to demonstrate the structure of the clitellum and 

 the truth of Cerfontaine's statements, yet Mr. Cole (p. 456) has 

 seen no nuclei in the long club-shaped cells! (to which by the way, he 

 gives the cumbrous name of »calceo-cutaneous« glands). He appears 

 to have obscured his preparations by some unnecessary method of 

 triple staining. 



1 Arch, de Biologie. X. 



