the Morphology of the Echinoderms. 103 



The above list might be considerably extended. I trust, 

 however, that it is long enough to show that the Crinoid 

 collections made bj the ' Challenger ' and ' Blake ' have not 

 been so completely barren of additions to our physiological 

 knowledge as Professor Perrier asserts. 



But the absence of physiological results has not been my 

 only sin of omission. According to Professor Perrier, I ought 

 to have worked out in detail the embryogeny of the common 

 Antedon rosaceus of the British seas, for the purpose of throw- 

 ing light upon the anatomy of the adult Crinoid ,• and he says 

 that I might have obtained the necessary materials at Eton, 

 since he procured them at Paris *. Has he forgotten the note f 

 which I sent him last year ^' On some Points in the Anatomy 

 of larval Comatulte " ? I stated in this note that I had con- 

 tinually felt the want of some knowledge of the organogeny 

 of the Crinoid type, and had therefore procured larvse of 

 various stages from Naples and Torquay, which had enabled 

 me to check some of the results obtained from an investiga- 

 tion of the adult anatomy. But as I was not professing to 

 write an exhaustive monograph of the Crinoidea, I did not 

 conceive it to be part of my duty to work out a detailed 

 account of the embryogeny of a type which is accessible to 

 every European naturalist. An already lengthy report would 

 have been swelled to gigantic dimensions. The number of 

 plates required would have increased from 69 (not 61, as 

 quoted by Perrier) to over 100, for Prof. Perrier tells us 

 that his own memoir on this subject is still incomplete, and 

 that thirty plates are already drawn. If the various naturalists 

 who have undertaken to report upon the different groups of 

 animals collected by the ' Challenger ' were expected to give 

 a complete anatomical and physiological description of each 

 group, and to supplement it by a detailed account of the 

 embryogeny of its representative in European seas, the publi- 

 cation of their reports would be delayed indefinitely ; and yet 



Crinoid. I can only say that I cannot understand how this impression 

 can have occurred to any one who has taken the trouble to read pp. 108 

 and 109 of the ' Challenger ' Report. 



* I would here express my sense of the courteous kindness of Prof. H, 

 de Lacaze-Duthiers, who offered to place at my disposal all the resources 

 of his laboratory at Roscoff, during June and July of this year, for the 

 purpose of working out the embryogeny of A^itedon rosaceus by the most 

 approved modern methods. I would have given much to have been free 

 to accept this invitation ; but my professional duties kept me in England 

 during both the months named, and, for the present at least, I must 

 leave the verification of Prof. Perrier's results to other hands, 



t Quart. Journ. Micr. Sci. N.S. vol. xxiv. pp. 319-327 (April 1884). 



