fe ee ea Y L g TEETE DEESA, O CQO R m 
E EAS. Or ? "Mig MN o 
Etui E 
1915] Rehder,— The Name of the Hemlock Spruce 61 
rule of priority. That Miller used the name canadensis for the White 
Spruce does not change the fact that canadensis is the oldest specific 
name for the Hemlock Spruce, since the Hemlock Spruce is the type 
of P. canadensis, as shown above, and since no subsequent author can 
change the type of a species previously described. Farwell asserts 
that Miller in splitting Pinus canadensis into two species could choose, 
if the names are of the same date, and that his choice could not be 
modified according to article 46 of the International Code. Now 
article 46 reads: “When two or more groups of the same nature are 
united, the name of the oldest is retained. If the names are of the 
same date, the author chooses and his choice cannot be modified by 
subsequent authors." As the wording shows this article does not 
refer to the division of species, but to the union of two or more species 
under one name. In article 47 which deals with the division of a 
species, nothing is said about the right of the author to choose, but the 
article rules that “if one of the forms was described earlier than the 
other, the name is retained for that form. 
Therefore taking as proved that the type of Pinus canadensis is the 
Hemlock Spruce, “canadensis” remains the correct specific name for 
this tree and Miller's specific appellation is a non-valid ! name having 
been formed contrary to the rules of nomenclature. More doubtful 
seems the validity of Miller's Abies canadensis, but as Miller does not 
quote Pinus canadensis Linnaeus as a synonym, Abies canadensis 
Miller may be considered a new name, and as the White Spruce had no 
earlier binomial appellation canadensis must stand as the oldest 
specific name, though the presence of an earlier homonym, viz. Pinus 
canadensis L., precludes the use of this specific name for the White 
Spruce, if transferred to the genus Pinus, and on the other hand the 
specific name “canadensis” cannot be used for the Hemlock Spruce, 
if transferred to the genus Abies, on account of the older Abies cana- 
1 The terms valid and non-valid have often been used indiscriminately for names 
which have become synonyms both for taxonomic or for nomenclatorial reasons. 
They should, however, be used for names only which belong to the latter category. 
This is made clear by the revised article 56 of the International Code (Act. Congr. 
Intern. Bot. Bruxelles 1910, I. 107) which reads: ''Dans les cas prévus aux articles 51 
à 55 le nom à rejeter ou à changer est remplacé par le plus ancien nom valable existant 
pour le group dont il s'agit et à défaut de nom valable ancien un nom nouveau (un 
binôme nouveau) doit être créé. Par nom valable on entend ici un nom et en particu- 
lier une combinaison de noms créés en conformité avec l'ensemble des règles de la 
nomenclature." A non-valid name always remains a synonym while a name which 
has become a synonym by change of generic or specific limitations may be revived 
at any time by another change in the taxonomic valuation of genera or species. A 
non-valid name, therefore, may be termed an unconditional synonym while a synonym 
for taxonomic reasons is a conditional synonym. 
