president's addeess. 283 



capacity of freshwater molluscs to survive in salt water, and vice 

 versa, require repetition and extension; so, too, do both Semper's 

 (56-8) and Varigny's (58a) experimental dwarfing of ZimtKsa. 



The influence of different foods on even the commonest of our 

 garden snails, easily as they may be kept under observation, is 

 practically unknown — nay, the ordinary food of many is not fully 

 understood, and Gain (!83, 2^) seems the only person who has conducted 

 pi'actical experiments on the subject. The habitat and mode of life of 

 many terrestiial moUusca, even the commonest, call for further 

 scrutiny : of this type of cecological investigation the Rev. A. H. 

 Cooke's paper (16), lately contributed to our Proceedings, is a good 

 example. 



All these things should claim our attention, for, to quote Kellogg 

 (.44. P- -^S?) : " Our work is to learn. To observe, to experiment, to 

 tabulate, to induce, to deduce. Biology was never a clearer or more 

 inviting field for fascinating, joyful, hopeful work. To question life 

 by new methods, from new angles, on closer terms, under more precise 

 conditions of control ; this is the requirement and opportunity of the 

 biologist of to-day. May his generation hear some whisper from the 

 Sphinx ! " But, as Huxley so wisely expressed it (31, p. 390) : 

 "Those who wish to attain to some clear and definite solution of the 

 great problems which Mr. Darwin was the first person to set before us 

 in later times must base themselves upon the facts which are stated in 

 his great work, and, still more, must pursue their inquiries by the 

 methods of which he was so brilliant an exemplar throughout the 

 whole of his life. You must have his sagacity, his untiring search 

 after the knowledge of fact, his readiness always to give up a pre- 

 conceived opinion to that which was demonstrably true, before you can 

 hope to carrjr his doctrines to their ultimate issue ; and whether the 

 particular form in which he has put them before us may be such as is 

 finally destined to survive or not is more, I venture to think, than 

 anybody is capable at this present of saying. But this one thing is 

 perfectly certain — that it is only bj^ pursuing his methods, by that 

 wonderful single- mindedness, devotion to truth, readiness to sacrifice 

 all things for the advance of definite knowledge, that we can hope to 

 come any nearer than we are at present to the truths which he struggled 

 to attain." 



WORKS EEFEREED TO. 



1. Beechee, (C. E.). "The Origin and Significance of Spines," etc. : Amer. 



Juurn. Sci., ser. it, vol. vi, 1898, pp. 1-20, 125-36, 249-68, and 329-59. 



2. Behnari) (F.). " Premiere (-Quatrieme) Note sur de developpement et la 



raorphologie de la Coquille chez les Lamellibranches " : Bull. Soc. geol. 

 France, .ser. iii, torn, xxiii, 1895, pp. 104-54; xxiv, 1896, pp. 54-82, 

 412-49 ; XXV, 1897, pp. 559-66. 



3. " llecherches ontogeniques et morphologiques sur la Coquille des 



Lamellibranches": Ann. Sci. Nat. (Zool.), ser. viii, torn, viii, 1898, 

 pp. 1-208, 12 pis. 



4. Beudant (F. p.). " Memoire sur la possibilite de faire vivre des MoUusques 



fluviatiles dans les eaux salees, et reciproquement, " 4to, Paris, 1816. 

 *^* His results are reproduced by Semper {infra, 08, p. 439). 



5. Blake (J. F.). " The Evolution and Classification of the Cephalopoda," etc. : 



Proc. Geol. Assoc, vol. xii, 1892, pp. 275-95. 



VQL, VIII. — JULY, 1909. 23 



