70 ANIMAL LIFE AND HUMAN PROGRESS 



We get many other fishes or parts of fishes sent for identifi- 

 cation : for example, frozen fish from Canada and South 

 Africa ; tinned fish from Portugal, California and India ; strips 

 of shark-skins of unknown origin ; fishes that eat mosquito 

 larvae, sent by medical officers from East Africa, Mesopotamia 

 and Salonica ; all these can be named by comparison with 

 specimens in the collection at South Kensington, and there 

 is no other institution in the Empire where this can be done. 



Systematic study of the species of fishes and of their 

 distribution and habits is the foundation of fishery develop- 

 ment and fishery legislation, and the economic importance of 

 fishes has led me to insist on the fact that all work connected 

 with the conservation and arrangement of the collection of 

 fishes in the Natural History Museum is economic work. 



I have mentioned insects because their economic im- 

 portance is so well recognised, and fishes because that is the 

 group that I know most about, but all groups of animals are 

 more or less directly useful or harmful to man, and must be 

 systematically studied. The great value of systematic work 

 on extinct animals is not generally recognised, but geology 

 depends on the accurate determination of fossils. They are 

 the clue to the age, sequence and nature of the rocks that 

 contain them ; from them we learn in what localities and at 

 what depth we shall find coal and other minerals, or where to 

 look for oil or for water. 



I have treated this part of the subject very shortly, and 

 I may refer you to an article entitled " National Work at 

 the Natural History Museum " in the Museums Journal for 

 February 1918 for a more detailed exposition of the practical 

 utility of the Museum, with examples of the matters that are 

 referred to that institution for information and advice. 



So much, then, for the utilitarian value of systematic 

 zoology : I now pass on to its relation to philosophical 

 zoology. 



Evolution is no longer a hypothesis — it may be termed an 

 established fact ; but the causes of organic evolution are 

 matters about which we may theorise to any extent. Of 

 recent years the experimental zoologists, the practical students 



