peesidext's addeess. 75 



Specialization must continue in so wide a tield, liemmed in by 

 so overwhelminfij a literature ; and as this is so, we seek relief 

 in a choice of departments. Concerning our conceptions of species 

 and varieties, Huxley (writing of the Canidte) suggested' that "it 

 may be as well to give up the attempt to define species, and con- 

 tent oneself with recording the vaiictics of pelage and stature 

 which accompany a definable type of skeletal and dental structure 

 in the geographical district in which the latter is indigenous." 

 Leaving this pregnant passage to your consideration, I would urge for 

 the future that specialization in the non-applied branches of Zoology 

 should go not along organological lines — one man studying shells, and 

 only shells— but zoological in the broad sense. Let each worker take 

 a scientifically definable group and determine all that he can of its 

 external and internal structure and palaeontology (^i.e. its morphology), 

 and its distribution, before deciding upon his classificatory system. 

 Indications of the dawn of this higher morphology are forthcoming 

 in our own " Proceedings," most conspicuously in Mr. Collinge's paper 

 on the "Myology of some Pulmouate Mollusca"; but I venture to 

 think that we are here going to too great an extreme. What we 

 require is a rational system, in which the study of structure as 

 related to function shall be recognized as a fundamental method 

 of discrimination between "characters" and "characters." Students 

 of more especially the Tunicata and Coelenterata no longer recognize 

 genera ancl species founded exclusively on the study of external 

 characters, and it follows that unless we Malacologists recognize 

 anatomy, we must fall behind. 



On analysis of a given series of forms we come to genera and species 

 which, in respect to salient morphological characters, depart widely 

 from the more ty[)ical members, and it is in the pursuit of these 

 points of departure that our most fruitful results are to be obtained. 

 This argument applies especially to the lower members of a group, 

 as is only too evident from the revolutionary results so recently 

 obtained by Pelseneer from the study of NucuW^ and by Bouvier 

 from that of Acfceon. 



Our immediate point of attack is thus clear. 



Form and symmetry are the outcome of physiological forces, and 

 the ultimate aim of biological inquiry is the determination of the 

 natural laws of which they are the expression. If this be admitted, 

 we cannot but deplore the casual dismissal of facts of structure so 

 remarkable as those pertaining to the peristomial region of such genera 

 as Cataulus, Papina, PupincUa, Spiraculum, and the Cyclophoridae 

 generally, or of the partial constriction of the apertures of many 

 terrestrial and marine Gastropods as "characters," and only characters. 

 It is binding on us for the future to give structural features such as 

 these the full and special attention which they deserve. 



In conclusion, let me point out that our newer classifications of the 



1 Huxley, Proc. Zool. Soc. 1880, p. 286. 



2 ArcMv. d. Biol., torn, xi, p. 153. 



