254 
AMERICAN JOURNAL OF BOTANY 
[Vol. 8 
precision by using the type method. I commend to the followers of the 
Vienna Code the proposal that the International Rules be modified by a 
recommendation to the effect that the application of names be fixed by 
means of nomenclatural types, this to apply retroactively. 
The American Code provides for fixing the application of names by 
means of types. It goes further and provides rules for determining the 
type. It should be emphasized that the acceptance of the concept of types 
does not involve the acceptance of a particular set of rules for selecting 
types. 
The code formulated by the Committee on Nomenclature of the Botan- 
ical Society of America is called the Type-basis Code of Nomenclature. 
Like the American and the Vienna codes, the rules of the Type-basis Code 
are founded on the principle of priority. The rules for selecting types of 
genera and of species are in conformity with this principle, while, as stated 
previously, the Vienna Code omits altogether the rules for selecting types 
(though type appears incidentally in Art. 45 as indicated above). It will be 
seen then that the chief difference between the Vienna Code and the new 
Type-basis Code is that the one ignores the subject and the other formulates 
rules for selecting types. If the Vienna Code could be modified to include 
a set of acceptable rules governing the selection of types, the most impor- 
tant difference between the two codes would disappear. 
Attention should here be called to the fact that selecting the type of a 
group does not validate the name of that group. Types are selected for 
both valid names and synonyms. It only means that if a certain name is 
used it should be so applied as to include the type. 
I will review briefly the proposed rules for selecting the types of genera. 
I will pass over certain particular cases such as those in which there was 
but one species in the genus as originally published, or in which the type was 
designated originally, and refer to the troublesome cases where there were 
several species included in the genus as originally published. This is true 
of many Linnaean genera, and the typification of these is basic so far as 
stability of nomenclature is concerned. There was an attempt at one time 
to select arbitrarily the first species as the type. This would be definite, 
but would often run counter to the historic development of the group and 
would cause so many changes in names as to introduce serious and needless 
confusion. The new code provides for selection by applying the rule of 
reason, taking into consideration all the factors in each case. In preparing 
a recent bulletin I found it necessary to typify over 300 grass genera. I will 
select a few examples from these. If the genus was used in his earlier 
works, Flora Lapponica or Flora Suecica, the type should be chosen from 
among those in the Species Plantarum that are cited by Linnaeus as being 
in one of the earlier works, since these are the species with which he was 
more familiar. Under Andropogon in the Species Plantarum Linnaeus 
describes 12 species. The name Andropogon was first used in the Flora 
