26o CARNEGIE INSTITUTION 



now quite unknown to science. It may be mentioned that as the re- 

 sult of some very fragmentary explorations (part of which were 

 directed by one of the writers) in the best known part of Europe 

 more than 60 new mammals have been discovered during the past 

 few years. 



In other classes a very great increase of the same kind is to be 

 expected, though probably to a less extent than in mammals. Add 

 to this the fact that the geographic distribution of practically no 

 widely spread species of Old World vertebrate is sufficiently well 

 known to permit its range to be mapped, and the importance of this 

 branch of the inquiry will be appreciated. As already pointed out, 

 much remains to be done in the study of those plants whose range 

 is supposed to cover parts of both hemispheres. From the results 

 already obtained it seems highly probable that a new conception of 

 the relationship of the members of most Holardic genera would 

 result from such work S)"stematicall5' conducted. 



III. Method of Conducting the Work. 



1. General organization. — The general organization proposed is 

 as follows : The work would be conducted under the joint super- 

 vision of the two directors, each of whom would take special charge 

 of the problems toward which his previous studies have been chiefly 

 turned, and each paying particular attention to the region in which 

 work has already been begun — that is, one at the extreme east, the 

 other at the west of the vast region which it is proposed to explore. 

 The care of the financial and administrative details of the survey 

 would be placed in the hands of an executive officer selected with, 

 special regard to business ability. The force of field naturalists 

 would, when fully organized, consist of from twenty to thirty ob- 

 servers and their assistants, specially trained for the work. In. 

 Washington a building should be provided for laboratories and tem- 

 porary installment of the collections. 



2. Organization of field force. — While the organization of the 

 field force must to a large extent depend on circumstances which 

 can not be foreseen, it is possible to gain a clear idea of the general 

 course to be pursued. Men already trained in the methods would be 

 at once placed in the more readily accessible regions, accompanied by 

 assistants who, when sufficiently experienced, would in turn become 

 the educators of the new men, and push on into more remote regions. 

 In this manner an efficient force would be built up and the work 

 carried on uniformly throughout, a consideration of the utmost im- 

 portance. Among the field naturalists those who show aptitude for 



