122 THE ORCHID REVIEW. [APRIL, 1907. 
reduced in size, the lip and the clavate spur each measuring about an inch 
in length. The flower is light purple, with the exception of the lateral 
sepals and the spur, which are pale green, and there is a pair of linear red 
blotches situated on the disc of the lip. The genus is nearly allied to. 
Habenaria. 
A hybrid has been raised from the two species above mentioned, namely, 
C. X kewense (O.R. xi. p. 219). It is a free flowering plant, fairly inter- 
mediate in character, and as easily grown as its two parents. C. Lowiana 
was the pollen parent. One species has the reputation of being a weed in 
the Clare Lawn collection (O.R. xiv. p. 300), and this is now known to be 
C. fastigiata, Thouars. 
cracls panei he 
EPIDENDRUM x KEWENSE: A MENDELIAN EXPERIMENT. 
THE interesting article, under the above title at page 58, from the pen of 
Mr. R. A. Rolfe, suggests the following notes. 
So far, I have found that direct experiments with Orchids on Mendelian 
lines have been difficult to carry out, owing partly to the time required to 
raise several generations and partly to cultural difficulties. Mr. Rolfe’s 
experiments at Kew with Epidendrum xX kewense are therefore most 
welcome, and he is to be heartily congratulated on his discovery of such a 
comparatively easy subject for Mendelian experiments in Orchids. Mr. 
Rolfe has very kindly sent me a batch of his second generation hybrids 
(known to Mendelians as the F, generation) : these are now growing well, 
and may possibly flower next year. 
With regard to the result, which we shall all await with much interest, 
Mr. Rolfe states that it has already been predicted from the Mendelian 
standpoint, viz.: One quarter of the seedlings should have purple flowers, 
like E. evectum, one quarter yellow flowers, like E. xanthinum, and one- 
half should be salmon-coloured, like E. x kewense. 
With reference to this prediction, I would like to point out that such a 
simple result can only be expected if the purple and yellow characters are a 
pair of characters which Mendelize (what Mendelians term “ allelomor- 
phic”). This may be so, but it seems to me rather unlikely in view of the 
results we have obtained in our experiments with purple and yellow flowers 
of other kinds of plants. 
The fact that the F, hybrid, E. xX kewense, is salmon-coloured, and 
the salmon-colour is ‘‘ due to an irregular marbling of light reddish purple 
over a yellow ground” (R.A.R. in O.R. xi. p. 6), suggests that the purple 
and yellow characters of the parents are not a Mendelian pair, but rather 
belong to two distinct Mendelian pairs, which may well be (I) presence and 
absence of purple, and (2) presence and absence of yellow, presence being 
dominant over absence in each pair. In sucha case the salmon-coloured 
