Rhodora 
JOURNAL OF 
THE NEW ENGLAND BOTANICAL CLUB 
Vol. 9. March, 1907. No. 99 
ON THE 
RULES OF BOTANICAL NOMENCLATURE ADOPTED 
BY THE VIENNA CONGRESS. 
INTRODUCTORY. 
No subject connected with systematic botany has in recent years 
been more earnestly discussed than the nomenclature question. 
Indeed, the prolonged and detailed controversies regarding this mat- 
ter must have been wearisome to many persons who, although inter- 
ested in plants, have had no leisure or desire to go into bibliographical 
technicalities. "To such persons, however, as well as to the profes- 
sional taxonomist, it should be a source of gratification that a con- 
siderable step has been taken toward international agreement on the 
points at issue. 
Before the rules and recommendations adopted by the Vienna 
Botanical Congress are here presented, it may be well to advert very 
briefly to the peculiar difficulties which have been involved in the 
nomenclature question and to recall the circumstances of the inter- 
national meeting at Vienna. 
For many decades it has been almost universally felt that botanical 
nomenclature should rest in a general way on the principle of priority 
of publication, or in other words, that the name of a plant was the 
first one assigned to it. Nearly all botanists of note have readily 
assented to this general idea, but great difficulties have arisen regard- 
ing the precise limitations which should be imposed upon the principle. 
'Thus, botanists of past generations, including such great leaders as 
the De Candolles, Bentham, the Hookers, Gray, von Martius, Eichler, 
Baillon, and others, have followed the principle of priority, yet they 
have made frequent exceptions based on considerations of taste and 
convenience as well as practicality. 
