82 PRESIDENTIAL ADDRESS- -SECTION D. 



Science pursued for its own sake widens the outlook of the* 

 individual and trains his reasoning powers. "Pure science" must 

 never be ignored, for the apparently academic and "useless" 

 researches of to-day may be of the greatest technical benefit to- 

 morrow. Examples of the truth of this in our own time are seen 

 in the researches of Metchnikoff in 1884 on phagocytic cells in the 

 blood of Daphnia, a transparent water-flea, when it was infested 

 by a yeast-like parasite called Monospora. The phagocytes engulfed 

 and digested the parasite. He had been working at phagocyte 

 cells earlier (1880), having been led thereto by his observations on 

 living jellyfish, sponges, embryos of Echinoderms and certain trans- 

 parent floating Gastropods, while Professor of Zoology at Odessa. 

 From these purely zoological studies he developed the great theory 

 of phagocytes and their importance in relation to inflammation 

 and the problem of immunity. Other examples are afforded by the 

 work of Ronald Ross on the role of mosquitoes in the transmission 

 of malaria, of Cailletet and Pictet on the liquefaction of gases, of 

 Rontgen on the X-rays, and the early experiments of Marconi. 

 Further, it is not for us to narrow the applications of science to 

 the limits of our own horizons, otherwise we stultify real advances 

 and limit ourselves to improvements in relative minutiae. Pure 

 science — the pursuit of knowledge for its own sake — eventually 

 gives a much greater and more comprehensive power of 

 dealing with practical problems on effective lines than if the pur' 

 suit is narrowly tied to strictly utilitarian ends. Nature can only 

 be effectively controlled when she is thoroughly understood, and 

 this thorough understanding can only be obtained when she is 

 studied for her own sake. 



To attempt to review the recent advances in a subject like 

 zoology is really to attempt an impossible task, for no one man 

 can nowadays keep abreast of advances in comparative anatomy of 

 animals, in cytology, in genetics, in animal parasitology, in 

 oceanography and fisheries, and at the same time have interests of 

 his own, that is, a corner of the subject on which he himself 

 researches. However, I think I may be able to put forward some- 

 interesting and even practical information from such an attempted 

 general survey of the work of zoologists during the last ten years, 

 paying less attention to the older branches of the subject like* 

 detailed morphology and comparative anatomy, but dealing with 

 the more recently studied branches of the subject. Of course no 

 claim to completeness can be put forward, and the element of selec- 

 tion has necessarily entered into a compilation such as the review 

 must largely be. 



Before proceeding further, however, I should like briefly to 

 express my views on the study of the subject of zoology. For the 

 progress of the science, study of the living organism itself — its 

 feeding, growth and reproduction — is essential. We must not for- 

 get the environment. Our methods must be those of observation 

 and experiment before we can tabulate inferences. There is a 

 danger nowadays of dividing the subject into relatively smalt 



