318 THE JOUilNAL OF BOTANY 



follow the T\^pe-basis Code have no inherent objection to a list of 

 nomina conservanda. We feel, however, that the present list was 

 not worked out upon the merits of each case but was somewhat 

 arbitrarily selected. Moreover, the accepted and rejected names of 

 such a list should be typified. The other two points are minor ones 

 that should not stand in the way of agreement. 



The chief item of difference is the concept of types. As this is 

 not contrary to the spirit of the International Kules we may hope 

 that it will be incorporated in those Rules and be retroactively applied. 

 At least a recommendation might be added to the effect that in 

 revising genera authors strive to establish them upon a type basis by 

 a careful study of the original publication and by recording the 

 species selected as the type of the genus. Items (2) and (4) above 

 depend largely upon the type concept. Item (6) is one that in 

 practice works so much more certainly according to the Type-basis 

 Code that followers of the International Eules are likely ultimately 

 to see the advantage of them, Avhen the}^ are examined without 

 prejudice. 



*A harmonizing of the two codes appears to be impossible if it is 

 maintained that the International Rules cannot be modified in any 

 essential, but only added to or interpreted. This is the belief in some 

 quarters, but I find no confirmation of this in the Rules themselves 

 and it is contrary to the spirit of codes and laws in general. They 

 should be modified to accord with the consensus of botanical opinion. 

 Otherwise they will be gradually abandoned. 



The typifying of genera should be done by those familiar ^\ith 

 the groups concerned. The study of names apart from the study of 

 the organisms to which the names are applied should be discouraged. 

 The tvpification will be a gradual process like all other botanical 

 investigation. 



As recorded on p. Ill, 1 am in favour of having an International 

 Committee appointed by each Congress to recommend to the suc- 

 ceedinp- Congress changes in the list of Nomina Conservanda, the 

 types of genera in questionable cases, and other matters of this sort. 

 Such a committee should be made up of experts on nomenclature. 



In this statement I am giving my personal views only. 



A. S. Hitchcock. 



U.S. Department of Agriculture, 

 Washington, D.O. 



FRIEDRICH EHRHART AND HIS EXSICCATE. 



Br James Brittei^, F.L.S. 



Some years ago, Mr. Arthur Bennett called my attention to 

 references to Ehrhart's Exsiccatce which seemed to show that the 

 extent and history of these collections were imperfectly known, and 

 suggested that it might be useful to publish a list of them. This I 

 now propose to do, confining mj'self mainly to such details of 

 Ehrhart's life as bear upon the Exsiccatce and upon his relations with 

 LinnfBus. A full autobiography extending from' his birth in 1742 

 until 1793 — written two years before his death — was found among 



