398 THE FUNCTION AND FIELD OF GEOGRAPHY. 



has no problem to solve. Professor Davis himself has given an example 

 of similar practical work in his elaborate paper on " The development 

 of certain English rivers " in the Geographical Journal for February, 

 1895 (Vol. Y. p. 127), and in many other publications. 



Another important problem to attack, and that in the near future, is 

 that of Oceanic Islands. I say in the near future, because it is to be 

 feared that very few islands now remain unmodified by contact with 

 Europeans. Not only have the natives been affected, both in physique 

 and in customs, but the introduction of European plants and animals 

 has to a greater or less extent modified the native fauna and flora. 

 Dr. John Murray, of the Challenger, has set a good example in this 

 direction by sending a young official from the ISTatural History Museum 

 to Christmas Island, in the Indian Ocean, one of the few untouched 

 islands that remain, lying far away from any other land, to the south- 

 east of the Reelings. 



What islands are to the ocean, lakes are to the land. It is only 

 recently that these interesting geographical features have received the 

 attention they deserve. Dr. Murray has for some time been engaged 

 in investigating the physical conditions of some of the remarkable 

 lakes in the west of Scotland. Some three years ago my friend and 

 colleague. Dr. Mill, carried out a very careful survey of the English 

 lakes, under the auspices of the Eoyal Geographical Society. His 

 soundings, his observations of the lake conditions, of the features on 

 the margins of and around the lakes, when combined with the investi- 

 gation of the regime of the rivers and the physical geography of the 

 surrounding country, conducted by such accomplished geologists as 

 Mr. Marr, afford the materials for an extremely interesting study in 

 the geographical history of the district. On the Continent, again, men 

 like Professor Penck, of Vienna, have been giving special attention to 

 lakes, that accomplished geographer's monograph on Lake Constance, 

 based on the work of the five States bordering its shores, being a 

 model work of its kind. But the father of limnology, as this branch 

 of geography is called, is undoubtedly Professor Forel, of Geneva, who 

 for many years has been investigating the conditions of that classical 

 lake, and who is now publishing the results of his research. Dr. 

 Forel's paper on " Limnology, a branch of geography," and the discus- 

 sion which follows in the report of the last International Geographical 

 Congress, affords a very fair idea in short space of the kind of work to 

 be done by this branch of the science. In France, again, M. Delebec- 

 que is devoting himself to a similar line of research; in Germany, Ule, 

 Halbfass, and others; Eichter in Austria, and the Balaton Commission 

 in Hungary. I may also here refer appropriately to Mr. Israel C. Eus- 

 sell's able work, published in Boston in 1895, on " The Lakes of North 

 America," in which the author uses these lakes as a text for a discourse 

 on the origin of lake basins and the part played by lakes in the changes 

 studied by dynamic geology. One of the best examples of an exhaus- 



