FEBRUARY, 19y07.| THE ORCHID REVIEW. 59 
be seen how far later events may modify any conclusions that might be 
arrived at from present indications. 
The Mendelian hypothesis, as I understand it, assumes that the marked 
colour difference between these two species is due to specific differences in 
the colour-bearing gemmules, by which the character is handed on with con- 
stancy. The result of hybridising the two is to combine these diversé 
tendencies, giving a more or less intermediate result, but it is assumed that 
in the hybrid the character-bearers remain unaltered, part being potentially 
purple and part yellow, the two on an average being present in equal 
numbers. When self-fertilised these gemmules have an opportunity of 
rearranging themselves, purple with purple, purple with yellow, yellow 
with yellow, and yellow with purple, and on an average these four combina- 
tions will occur in equal numbers, according to the law of averages, or 
twenty-five per cent. each. Thus twenty-five per cent. of the seedlings 
should have purple flowers, like E. evectum, and twenty-five per cent. 
yellow flowers, like E. xanthinum, but as purple with yellow gives the 
same result as yellow with purple (the two classes being indistinguishable) 
the remaining fifty per cent. should be salmon-coloured, like E. xX kewense. 
Conversely, there should be no intermediate stages between these three 
classes. The experiments above described should throw a very interesting 
light on the question, because we are dealing with plants having well- 
marked specific differences, and distinct lines of descent, not with inbred 
races, and the assumed ‘‘ Law of Gametic Purity” may not apply in the 
same way. It seems to me that dissociation of mixed or hybrid character 
is a much simpler explanation of many of the phenomena that are asso- 
ciated with Mendelism, and need not be of universal application, as the 
so-called ‘“* Law of Dominance” is now acknowledged not to be. The 
Laws of Heredity, whatever they may be, are not of merely partial 
application. R. A. ROLFE. 
ORCHIDS AT KEW. 
THERE has been a fine display oe Orchids at Kew throughout the winter, to 
which the fine old Cattleya labiata, the Mexican Lzlias, Paphiopedilum 
insigne with its hybrids, and latterly the deciduous Calanthes have con- 
tributed largely. Owing to the ravages of fog, however, there has been 
a considerable falling off during the past fortnight, though a good many 
interesting things are in bloom. One of the best is the charming little 
Pleione yunnanensis, figured at page 81 of our last volume, but the fog 
took some of the buds, one flower alone escaping. Epidendrum fragrans, 
which is flowering freely in the Warm house, passed through the fog 
unscathed, and its fowers are deliciously fragrant, so that the plant is very 
attractive when well grown. Others in bloom are E. evectum and E. 
