46 Rhodora [Marcu 
For this purpose preliminary particles or letters that do not, strictly speak- 
ing, form part of the name, are suppressed, and the first letters are given 
without any omission. If a name of one syllable is long enough to make it 
worth while to abridge it, the first consonants only are given (Br. for Brown); 
if the name has two or more syllables, the first syllable and the first letter of 
the following one are taken, or the two first when both are consonants (Juss. 
for Jussieu; Rich. for Richard). When it is necessary to give more of a name 
to avoid confusion between names beginning with the same syllables, the 
same system is to be followed. For instance two syllables are given together 
with the one or two first consonants of the third; or one of the last charac- 
teristic consonants of the name is added (Bertol. for Bertoloni, to distinguish 
from Bertero; Michx for Michaux, to distinguish from Micheli). Christian 
names or accessory designations, serving to distinguish two botanists of the 
same name, are abridged in the same way (Adr. Juss. for Adrien de Jussieu, 
Gaertn. fil. or Gaertn. f. for Gaertner filius). 
When it is a well established custom to abridge a name in another manner, 
it is best to conform to it (L. for Linnaeus, DC. for De Candolle, St.-Hil. for 
Saint-Hilaire). 
In publications destined for the general public and in titles it is preferable 
not to abridge. 
Section 6. On names that are to be retained when a group is divided, 
remodelled, transferred, or moved from one rank to another, or 
when two groups of the same rank are united. 
Art. 44. A change of characters, or a revision which involves the 
exclusion of certain elements of a group or the addition of new ele- 
ments, does not warrant a change in the name or names of a group, 
except in cases provided for in article 51. 
Examples.— The genus Myosotis as revised by R. Brown differs from the 
original genus of Linnaeus, but the name has not been changed, nor is any 
change allowable. Various authors have united with Centaurea Jacea L. 
one or two species which Linnaeus had kept distinct; the group thus consti- 
tuted must be called Centaurea Jacea L. (sensu ampl.) or Centaurea Jacea L. 
(em. Visiani, em. Godron, etc.); the creation of a new name such as Centaurea 
vulgaris Godr. is superfluous. 
Art. 45. When a genus is divided into two or more genera, the 
name must be kept and given to one of the principal divisions. If 
the genus contains a section or some other 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. 
Examples. — The genus Helianthemum contained, according to Dunal 
(in DC. Prodr. I. 266-284 [1824], 112 well-known species distributed in nine 
sections; several of these sections have since been raised to generic rank 
(Fumana Spach, Tuberaria Spach) but the name Helianthemum has been 
kept for the divisions grouped round the section Euhelianthemum. — The 
genus Convolvulus L. em. Jacq. was divided into two by Robert Brown in 
1810 (Prodr. fl. Nov. Holl., p. 482-484), who gave the name Calystegia to one 
