May, 1914.] THE ORCHID REVIEW. 133 
|\@| THE LONDON BOTANICAL CONGRESS. S| 
NOTICE of the International Botanical Congress to be held in London 
from May 22nd to 29th, 1915, was given at page 360 of our last 
volume. A second circular shows that the Program of work deals largely 
with fossil and Cryptogamic botany (for which subjects Committees and 
Sub-Committees have been appointed), with discussions of motions relating 
to points not settled by the preceding Congresses. It is remarked that the 
revision of the Rules of Nomenclature occupied three Congresses, at Paris, 
Vienna, and Brussels, and it is highly desirable that the work should be 
completed in London, and botanists are requested to examine carefully the 
points which still require consideration and to formulate propositions to 
this end. : 
A supplement to the Rules, based on propositions submitted, will be 
issued before January next, and a later circular will supply information on 
the internal arrangements of the Nomenclature Section of the Congress. 
The following is a copy of the proposition that has been submitted for 
consideration :— 
SECTION V.—NAMES OF HyBRIDS AND HALF-BREEDS (MULES). 
Our knowledge of hybrids has increased enormously during the last 
decade, and as the rules governing their nomenclature are out of date, and 
in some cases contradictory, I propose that Section V. of the Vienna Rules 
be entirely recast, incorporating some of the amendments made at Brussels, 
as follows :— 
Hybrids arise through the intercrossing of distinct species, and are 
common in certain groups of plants, both in gardens and in a wild state, 
the latter chiefly arising through insect agency where allied species grow 
intermixed. Hybrids may occur between species of the same genus or of 
different genera, and if fertile they may recross with their parents or with 
other species, in some cases with those belonging to different genera. 
Crosses between varieties of the same species are not hybrids, and do not 
come withing the limits of this section. 
(a) Primary Hyprips.—Hybrids between species of the same genus, or 
presumably so, are distinguished by a formula (e) and, whenever it seems 
useful or necessary, by a name. All hybrids obtained by crossing the same 
two species, or their varieties, must bear the same specific name (/), any 
distinct forms being indicated by the addition of varietal names (g). 
(6) BIGENERIC HYBRIDS.—Hypbrids between species of two different 
genera receive a generic name formed by combining the generic names of 
the two parents, or portions of them, into a single word, composed as far 
as possible so that the names of the two parents entering into the 
