Nov.-Dec., 1917.] THE ORCHID REVIEW. 243 
and its absence recessive. Part of the confusion in this matter 
has undoubtedly resulted . . . from the failure to recognise the 
distinction between the two classes of characters. The 9:3:3:1and 3:1 
ratios are used freely and with assurance, whereas there are really no 
such ratios. There appears to be a lack, in usage at least, of appreciation 
of the distinction between characters which are allelomorphic to each other, 
never to an absence, and those characters which are allelomorphic only to 
their absence, never to each other or any other characters, and which exist only 
in relation with, and in addition to, characters allelomorphic to each 
other.” 
The title is “ Studies of inheritance and evolution in Orthoptera ”’ ; had 
it been Orchids we might have been able to follow the paper further with 
profit, but the remarks are significant, and suggest the necessity of a 
nomenclature more in accordance with the facts. When a character is 
allelomorphic to its absence (whatever that may mean) it is a nice question 
whether it is allelomorphic at all, and a Mendelian pair that is built up on 
the same principles may be only a single one. It may yet be discovered 
that Mendel himself was under no such illusions about the fundamental 
principle of the separation of the units, for he spoke of characters entirely 
and permanently accommodated together (the italics are his), and he added : 
“For the history of the evolution of plants this circumstance is of special 
importance, since constant hybrids acquire the status of new species.” 
It would be interesting to know what Mendel would have thought of the 
recent claim that new species only arise by crossing, a proposition that is 
altogether against the weight of evidence. For our part, we doubt whether 
Mendelian research has yet produced any direct evidence as to the way that 
Species originate in nature. 
n a notice of this plant in 
al, under the name of A. 
On page 66 he 
ving flowers 
AERIDES HYBRIDUM.—At page 208 you mentio 
the 6th edition of Williams’ Orchid Grower’s Manu 
Dominianum. I havea copy of the 5th edition (1877). 
gives the following: ‘‘ A. Dominianum.—A garden hybrid, ha 
the colour of those of A. Fieldingii, with the markings and shape of A. 
affine. It is very rare at present. One of the most beautiful varieties 
which are enriching our collections as the result of hybridising. It is the 
produce of a cross between A. Fieldingii and A. affine, producing rich 
rose-coloured flowers.” I do not know whether this account differs, but 
it may be of interest as of earlier date.—BARTLE GRANT, Wilmington 
House, Dartford, Kent. 
(Substantially different. We are afraid the plant has been lost. —ED.] 
