May, 1921] 
HITCHCOCK — THE TYPE CONCEPT 
division which, judging by its name or its species, is the type or the origin of the group, the 
name is reserved for that part of it. If there is no such section or subdivision, but one of 
the parts detached contains a great many more species than the others, the name is reserved 
for that part of it. 
Let US apply this rule to the Linnaean genus Panicum. There are 20 
original Linnaean species. Several of them, including P. miliaceum and 
its allies, belong to the genus Panicum as delimited by most modern botan- 
ists. Among the 20 are also P. italicum and its allies, now generally dis- 
tinguished as Setaria or Chaetochloa. But Panicum italicum is the historic 
type of Panicum, that is, the species which was known as Panicum by pre- 
Linnaean authors and the one which I should interpret as, "judging from 
its name or its species, is the type or the origin of the group," and therefore 
the segregated genus containing it should have retained the name Panicum. 
However, in the process of taxonomic and nomenclatural development of 
the various species involved, this procedure was not followed. If botanists 
wish to retain the name for the allies of Panicum miliaceum, the simplest 
method to insure this result is to select Panicum miliaceum as the type of 
Panicum. 
The Linnaean genus Holcus, presenting certain complications, illustrates 
the advantage of the type method. The name in pre-Linnaean literature was 
applied to the sorghums, but in the Species Plantarum Linnaeus unites with 
the three species of the sorghum group four other species of diverse rela- 
tionships, one of which is Holcus lanatus, the only one of the species belonging 
to Holcus as now recognized by European botanists. The Vienna Code 
provides (Art. 19) that 
It is agreed to associate genera, the names of which appear in this work [Species Plan- 
tarum] with the descriptions of them in the Genera Plantarum ed. 5 (1754). 
According to the Vienna Code (as well as to the American and Type- 
basis codes) the name Holcus should be applied to the sorghums and this I 
have done, since the author's concept is most accurately interpreted by his 
own description. But when the aggregate included under Holcus by Lin- 
naeus in 1753 was divided, a century or more ago, the soirghums and species 
of other genera were taken out and the name Holcus was left for H. lanatus, 
which until recently has generally borne that name. The followers of the 
Vienna Code have accepted current usage regardless of the rules of that 
code. Would it not be simpler and more definite to make an exception and 
to crystallize current usage by fixing Holcus lanatus as the type of Holcus? 
Examples could be multiplied indefinitely. Apparently the rules of 
the Vienna Code were left indefinite in order that botanists should not be too 
much restricted in the application of names and should have some freedom 
to. use personal judgment. It is impossible to foresee all contingencies and 
to provide for them by definite rules. As shown above, when, in par- 
ticular cases, the rules lead in the wrong direction they are likely to be 
ignored. The desired results can be accomplished with much greater 
