134 tite jouknal of botany 



Ttpificattox of Geneea. 

 Most botanists will probably agree with Dr. Peiinell that all 

 generic names should be typitiecl. It seems to show a lack of resom'ce, 

 however, "" to rule out genera so well described as those of Jussieu's 

 Genera Flaniariim''^ on the ground that they cannot be associated 

 definitely w4th a given species. Surely the obvious course to follow 

 is to choose a type-species for each current but untA^pified generic 

 name. As Mr. A. S. Hitchcock lias pointed out in his admirable 

 article on " The Type Concept in Systematic Botan}- " (Amer. Journ. 

 Bot. viii, 251; 1921), "in the early days of taxonomy a name was 

 applied to a concept rather than to an entity. A generic name 

 was based upon all the known species of the genus ; a specific name 

 w^as based upon all the know^n specimens of the species." Since many 

 genera, therefore, actually had no type-species, the retroactive fixation 

 of generic types is largely a matter of convenience. This is virtually 

 recognized in the Type-basis Code, Article 6, which permits such 

 exceptions as may be validated by an International Nomenclature 

 Commission. Thus although, according to the Code, the historic type 

 of the genus Panicum is P. italicum, which is a Setaria, Mr. Hitchcock 

 suggests that P. miliaceiim should be selected as the type-species in 

 order that the cui-rent usage of the generic name mav be retained 

 (1. c. 253). 



The far-reaching consequences which the adoption of the Type- 

 basis Code might entail have been briefl}^ indicated by Dr. Schinz 

 (Vierteljahrsschr. Nat. Ges. Zurich, Ixvi. 916; 1921), but have 

 perhaps not been generally appreciated. The fixation of generic types 

 is still in its infancy, yet nearl}^ 13 per cent, of all changes in the test 

 group of genera {vide siipra^ is due to this cause. According to Di\ 

 Britton, the type-species of Sisi/mhrium andl^iysimifm are Sisymhriiim 

 Nasturtium-aquatlcum and ]£rifsimum officinale respectively. The 

 result is that Nasturtium becomes Sisi/mbrium, Sisymhrium becomes 

 J^rysiniuni, and JSrysinmm becomes Cheirinia (111. Fl. ed. 2, ii. 162, 

 172, 173). Such revolutionary^ changes might, however, be avoided b}'- 

 the validation of " substitute tj^pes " under Article 6, as suggested 

 by Mr. Hitchcock. I have therefore great pleasure in supporting his 

 proposal for the appointment of an International Committee for the 

 purpose of fixing generic types and "substitute types," recommending 

 new " nomina conservanda " etc. Possibly a smaller committee than 

 that suggested might be desirable. 



My twelve suggestions may now^ be review^ed in the light of the 

 criticism which has been offered. Drs. Schinz and Thellung consider 

 that no definite decision of the Vienna Congress should be reversed, 

 and therefore regard suggestions 1, 2 B, 2 C, 3, 4, and 6 as inadmissible. 

 It seems preferable, however, to consider each suggestion on its ow^n 

 merits. 



1. Revocation of Art. 36. — I agree with Mr. Eehder (Journ. Arn. 

 Arb. i. 51 ; 1919) that Art. 36 should be made a Kecommendation. 

 Mr. Groves has suggested that it should be amended by substituting 

 for the words " valid only when accompanied by a Latin diagnosis," 

 the words '* valicl only when accompanied by a diagnosis in Latin or 

 in one of the modern languages which employs Koman Characters " 



