588 Underwood: The genus Alcicornium 



ii 



narrative of his report on the voyage of /' [frame says fpage 48) : 

 On trouve de plus une fougere tres-remarquable qui abonde sur 

 les rameaux de tous les tamariniers : c*est V Acrostichuni alcicorne, 

 ou du moins une espece ou variete du genre {Aid cor nil mi) qu'on 

 ne manquera pas de faire de ces plantes des qu'elles seront mieux 

 examinees." We can hardly discern the distinction between this 

 case and that of Elaphoglossum, and we must consider the genus 

 Alcicaniium as ** r//^ pubhshed '' by the association of a generic 

 name with a type species ; and Mr. Christensen, who includes 

 among certain just criticisms * of my recognition of fern genera of 

 the Old World a rejection of this genus, is surely inconsistent in 

 taking up Elaphoglossum while denying validity to Alcicornhtvi. 

 It is true that in the latter case Gaudichaud withdrew his name in 

 the same work (page 307), but there was an interval of nearly two 

 years between the first publication and the second, f during which 

 Desvaux published the genus Platycermm more formally, and 

 Gaudichaud with the characteristic '*aprcs vous, monsieur" of 

 French courtesy simply withdrew his genus in deference to 

 Desvaux. It is a generally recognized principle .of biological 

 nomenclature that *' a name is a name," and that a genus once pub- 

 lished cannot be withdrawn from nomenclature even by its own 

 author. The only reason for withdrawing a published name is the 

 proof that it is either a synonym or a homonym. If Desvaux had 

 not published Platyceriitm in 1827 no one would have hesitated to 

 cite Alcicornhnn as dating, from its first publication at page 48 of 

 Freycinet's voyage in 1826. On the principle of priority of publi- 

 cation, therefore, we must accept the name Alcicornuim as the 

 proper designation for the unique genus of stag-horn ferns. | If 



* Christensen. On the American species of Leffockilus sect. Bolbitis. Bot. 

 Tidssk. 26 : 283-300. 1904. Much of Mr. Christensen's criticism is based on a mis- 

 conception of my point of view ; our conceptions of the limitations of genera are wholly 

 different. In the single case oi Beivisla I had overlooked the synoptical publication 

 of the genus in which the order of the species is inverted from that in its more formal 

 publication in the text. This transfers Belvisia from Acrostkhian spuatuvi to A^ 

 septentrionale [Asplenium septentrionale Hoffm.). 



f The date of the publication of pages I-48 of Freycinet's voyage is 1826. The 

 date of the publication of pages 265-312, including the withdrawal of Alcicornium^ 

 is 1828. Cf. Jour. Bot. 39 : 206. 1901. 



J In raising this group to a tribal alliance (Bull. Torrey Club 30: 672) we over- 

 looked the fact that this had already been done by the acute John Smith in bis Hisfoiia 

 FilicuiJi^ 122, 1875. We would now exclude from the tribe the peculiar genus 

 Cheiropleuria placed in this alliance by Diels (Die nat. Pflanzenfam. i* : 336) as more 

 properly representing, in its vascular system particularly, a high degree of differentiation 

 in the tribe Acrosticheae. 



