president's addkess. 219 



Dr. H. P. Blackmore, iu which,' convinced of the invariable associa- 

 tion of certain Aptychi and Belemnites, he would have us believe that 

 Aptychus leptophijllus, A. Fortlookii, and A. ruffosus, were appur- 

 tenances of the Belemnite organism, homologous forsooth with the 

 pro-ostracum ! His arguments show complete disregard of a sense of 

 proportion of the cephalopod body, and lack of knowledge of the 

 elements of anatomy indispensable to the orientation of its parts. We 

 wish we could accept them, but we cannot. 



The details in development of the radula from an epidermal invagi- 

 nation have in Paludina been worked out by Bloch.- The investigations 

 of Pelseneer, Brook and Drew, and F. Bernard, boforementioned, once 

 again impress on us the importance of ' convergence ' ; and a result 

 like Hedley's relegation of certain species of Angasella, Chloritis, and 

 Thersites to Tate's genus Xantliomelon,^ from a knowledge of their 

 visceral as well as their conchological characters, once more emphasizes 

 how indispensable is a knowledge of the anatomy of recent forms if 

 truly scientific progress is to be made. 



In the way of experimental work, popular interest centres on the 

 oyster, upon which, in relation to ty|)hoid and other diseases, official 

 reports have appeared * during the year. The creature has proved itself 

 a veritable arch-glutton of germs, sewage, and abominations generally. 

 The discovery by Professors Herdman and Boyce that the typhoid 

 bacillus does not flourish in clean sea- water, and (in conjunction with 

 other investigators) that neither sewage nor fresh water are favourable 

 media to its existence, is reassuring, and calls for a suspension of 

 judgment on the luscious bivalve. 



Boyce and Herdman,^ Chatin," De Bruyne,' and others, have 

 considerably advanced our knowledge of the so-called ' greening ' of 

 the oyster, erroneously thought by some to be a secretory process. 

 Special interest attaches to their discovery tliat it marks the removal 

 of deleterious matter by the agency of migratory cells ; and it is for 

 us a cause of congratulation that the year which has seen Lister 

 elevated to the peerage finds our Mollusca in the thick of the phago- 

 cytosis blood-gland inquiry, from which mankind has more to hope 

 than from the armed forces of the woiid. 



Nor are our chosen class of animals to be longer excluded from the 

 field of experimental physiology, for they have creditably contributed 

 to a recent comparative study of respiratory exchange with the outside 

 world ** at dift'erent periods of growth and under experimental 

 influence. 



1 n. P. Blnekmore, Geol. Mag., 189G, pp. 529-33. 



- I. Bloch, Jenaische Zeitschr., Bd. xxx, p. 356. 



3 C. HecUey, Rep. Horn Expecl., pt. ii (Zool.), p. 224. Cf. also Suminaiy, p. 15'?. 



* " Oyster Culture iu Relation to Disease" : 24tli Auu. Rep. by Medical Ollicer 



Loc. Gov. Board, 1^96. 

 ^ R. W. Boyce and AV. A. Ilerdman. Rep. Laucasliire Sea Fisli Lab., 1895, p. (i, 



and also Brit. Assoc. Rep., 1896, p. 663. 

 ^ M. J. Chatiu, Coniptes Reud., torn, exxii, ])\^. 796 aud 1556. 

 '' C. de Rruyue, Arch. d. Bio!., torn, xiv, p It 1. 

 '* Cf. II. M. Veruou, Jouru. I'hysiol., vol. xix, p. 28. 



