May 26, 1905.] 



SCIENCE. 



829 



designation of plants,' than the method of 

 applying the name according to tradition, 

 authority or consensus of opinion. Instead of 

 this, then, it is proposed to discuss briefly the 

 practical difficulties which may arise in this 

 method of types, and bow these difficulties 

 may be overcome. 



The code mentioned above states in regard 

 to the application of names (Canon 14) the 

 following : ' The nomenclatorial type of a spe- 

 cies or subspecies is the specimen to which the 

 describer originally applied the name in publi- 

 cation.' 



Where an author in connection with an 

 original description has indicated a definite 

 specimen, there is usually no difficulty in de- 

 termining the type. When an author indi- 

 cates only the number or other data occurring 

 on the label in numbered sets prepared for 

 distribution, but does not specify a particular 

 specimen, the type would be the one from 

 which the author drew up the description and 

 would presumably be in his herbarium. The 

 other specimens would then be designated as 

 duplicate types. Not infrequently the author 

 draws the description from all the specimens 

 of a given number in a set, in which case the 

 specimen in the herbarium of the author, or 

 of the institution at which he is located, must 

 be arbitrarily chosen as the tj^pe. 



Many difficulties arise in determining the 

 types of the older authors, as the practise of 

 designating specimens as such is quite recent. 

 When a name is based vipon a single specimen 

 this becomes the type though not actually 

 designated as such. If more than one speci- 

 men is cited, but none designated as the type 

 it becomes necessary to select one of these. 



The above mentioned code provides that 

 * When more than one specimen was originally 

 cited, the type or group of specimens in which 

 the type is included may be indicated by the 

 derivation of the name from that of the col- 

 lector, locality or host.' (Canon 14, a.) Fur- 

 ther, if no type can be selected on this basis, 

 ' Among specimens equally eligible, the type is 

 that first figured with the original description, 

 or in default of a figure, the first mentioned.' 

 (Canon 14, b.) 



There are manj' original descriptions, how- 



ever, in which no specimens are cited, but 

 instead the locality or range may be given. 

 It then becomes necessary to consult the au- 

 thor's herbarium or the herbarium in which 

 his plants are deposited. Specimens which 

 bear the name in his handwriting should be 

 given preference in the selection, and of these 

 the type is the one from the locality first men- 

 tioned, or the one collected by the person for 

 whom the species is named. Even with these 

 aids in selection it may be necessary to arbi- 

 trarily select a certain specimen from among 

 those equally eligible. This should be done 

 by a monographer and only after a careful 

 examination of the available data. Where 

 possible the most perfect specimen should be 

 selected or the one most nearly corresponding 

 to the original description. For example, if 

 the species is known to produce rhizomes and 

 only one of the otherwise available specimens 

 showed these organs, this specimen might be 

 selected. Occasionally the original descrip- 

 tion includes more than one form and the 

 specimens are correspondingly diverse. It is 

 then very necessary to use particular care in 

 the selection of the type. Muhlenberg de- 

 scribed Panicum depauperaium without indi- 

 cating a type. In his herbarium deposited 

 in the Philadelphia Academy of Natural Sci- 

 ences is the sheet of specimens upon which the 

 name is founded. In this sheet are plants 

 of P. linearifolium Scribn. and two forms of 

 what is now considered to be P. depauperatum 

 Muhl., one with glabrous sheaths and one 

 with pilose sheaths. From the description one 

 can not determine which one of these forms 

 was intended. Probably all were included as 

 one species. Since the form with smaller 

 spikelets has been distinguished by Professor 

 Scribner as P. linearifolium the type of P. 

 depauperatum should be selected from the 

 specimens with large spikelets. Wlien the 

 two or more species confused by one author 

 are distinguished by a later author, this au- 

 thor should determine the type. The old 

 specific name should remain with the type and 

 the new name be based upon a different type. 

 Much confusion has arisen because of failure 

 to follow this rule. If the original specimens 

 are made up of both species, the author of the 



