48 REPORT OF THE SECRETARY. 



Having offered his services to .the United States Fish Commission in 

 any way connected with his labors, he was requested to bring over a 

 consignment of German carp, a fish which promises to be of great value 

 in American pisciculture. This was done by him, and be delivered to 

 the United States carp ponds, in Washington, a number of these fishes 

 in a healthy condition, which, it is hoped, will, in a few years, be the 

 progenitors of a large number of that species of fish. 



In order to enable Dr. Finseh to carry on his Polynesian researches to 

 better advantage and at less expense to himself, free passes and reduced 

 passage tickets for himself and party were obtained from several of the 

 transcontinental railroad companies. The Smithsonian Institution pro- 

 vided Dr. Finseh with a partial outfit for marine exploration, including a 

 supply of alcohol for the preservation of reptiles and fishes. Dr. Finseh 

 proceeded first to the Sandwich Islands, and then to the Fijis, and at 

 the latest advices he had reached one of the groups of the Marshall 

 Islands. 



EXCHANGES. 



As was explained in the report for 1878, the system of international 

 exchanges organized by the Smithsonian Institution nearly thirty years 

 ago has long been considered one of its most important functions, and 

 no greater obstruction to the intercourse between the scientific institu- 

 tions of the Old World and New can be imagined than that of an inter- 

 ruption of this work. As already stated, an organization intended pri- 

 marily to aid in the prompt transmission of the publications of the Insti- 

 tution to its correspondents, at home and abroad, was extended so as to 

 include the corresponding exchanges of other institutions ; this has now 

 resulted in furnishing by far the most extensive system of exchanges in 

 existence, the benefits of which are experienced and appreciated all over 

 the world. 



The foreign agencies employed in the Smithsonian exchanges are of 

 three classes. 



First. Individuals or firms, some of them salaried by the Institution 

 and devoting more or less of their time to its work. 



Second. Learned societies or universities, which do on a small scale in 

 their respective countries what the Smithsonian Institution does on a 

 largo- scale for the world in general. 



Third. Special government bureaus of international exchange, organ- 

 ized for the purpose. It is quite probable that the number of this class, 

 now restricted to four, namely, the Commission Beige des ^changes 

 internal ionaux, the Commission Francaise des ^changes internationaux, 

 the Bureau central scientifique of Haarlem, and the Bundes Canzlei 

 for Switzerland, Mill be increased until, possibly, in time, the greater part 

 of the service in Europe in connection with the Smithsonian Institution, 

 may be performed by them. This will, of course, constitute a very de- 

 sirable ;iid to the Smithsonian Institution and to the second class men- 

 tioned, especially as to the expenses of the work. 



