﻿Le Jolis-Howe: Porella once more 97 



of the Paris code, with its provisions for various exceptions to the 

 law of priority, led to such diversities of usage in matters of 

 nomenclature, especially, perhaps, in the Phanerogamia, that 

 working systematists in various parts of the world have thought 

 to secure greater stability of nomenclature in the end by closer 

 adherence to the priority principle, even though this principle is 

 not so easy to apply as to formulate and unfortunately calls for 

 the disappearance of many familiar names. Practically the sole 

 limitation imposed on priority by the Rochester code is the initial 

 date 1753. Three of the articles of this code are : 



I. The Lazv of Priority — Priority of publication is to be regarded 

 as the fundamental principle of botanical nomenclature. 



II. Beginning of Botanical Nomenclature .—The. botanical no- 

 menclature of both genera and species is to begin with the publi- 

 cation of the first edition of Linnaeus' " Species Plantarum," in 



1753. 



* # ■* * * * 



V. Publication of Genera. — Publication of a genus consists 

 only (1) In the distribution of a printed description of the genus 

 named; (2) In the publication of the name of the genus and the 

 citation of one or more previously published species as examples 

 or types of the genus, with or without diagnosis. 



In accordance with the spirit of the second part of Article V., 



I would, therefore, with Lindberg, Spruce, Carrington, Pearson, 



Mitten, Arnell, Underwood, Evans, Kaalaas, Rossetti, and others, 



(at times, also, Stephani, Massalongo and Schiffner), take the 



ground that Porella is not a nomen nudum with Linnaeus. It is 



true that he never saw the plant, but he did give it a place among 



his genera and species, and referred to the figure and description 



given by Dillenius, and this saves the Porella of Linnaeus from 



being a " bare name." 



It is incontestable that Dillenius made serious errors in his in- 

 terpretation of the characters of the plant and that these are em- 

 balmed in the name Porella. Yet the meaning of his description and 

 figures was sufficiently clear to give Dickson (on receiving what was 

 perhaps the first specimen of the plant thereafter sent from America 

 to Europe) ground to " suspect " that his plant and that of Dillenius 

 were « the same " which he easily proved to be the case by com- 

 paring the specimens. And it seems to me that his figures and 

 description were sufficiently clear to have enabled others besides 



