MUSEUMS AND RESEARCH 71 



of heredity, have tried to solve the great problem of the origin 

 of species by new methods and with results that they regard 

 as satisfactory. No one can be more sensible than I am of the 

 great theoretical interest and practical utility of the results 

 obtained by the experimental study of the science of breeding ; 

 but — speaking as a systematist — I must confess that these 

 results seem to me to throw but little light on the origin of 

 species and still less on the evolution of adaptations. 



With regard to the propriety of a systematist speaking on 

 this subject I cannot do better than quote some sentences 

 from Professor Dendy's presidential address to the Quekett 

 Microscopical Club in 1916 : — 



" Some of us think that the science of biology includes 

 the study of the whole organic world in all its aspects, and 

 that the systematic description and arrangement of plants and 

 animals constitutes an indispensable part of the foundation 

 upon which all biological theory must be based. Indeed, I 

 would go further, and even say that no biologist without some 

 considerable experience of systematic zoology or botany is 

 really competent to form a judgment on such problems as 

 the nature and origin of species and varieties. The true 

 systematist is just as much inspired with the enthusiasm of 

 research and the thirst for knowledge as the experimental 

 biologist. The difference between the two Ues in the fact 

 that the experimental biologist confines his attention to the 

 solution of certain fixed and definite problems suggested by 

 his own very limited knowledge of the organic world, whilst 

 the systematist studies the results of the infinitely varied 

 experiments which Nature has been performing upon living 

 organisms ever since they first appeared upon our planet." 



The systematist indeed often gets very clear indications 

 as to where, when and under what conditions species may 

 have originated ; I will illustrate this by some examples from 

 my own work. 



Many marine fishes are anadromous — that is to say, they 

 ascend rivers to breed in fresh water. Such fishes often form 

 permanent fresh-water colonies, in rivers or in lakes, and in 

 course of time these may become distinct races or even species. 



