—— 
THE ORCHID REVIEW. 
VoL. XI.] APRIL, 1903. [No. 124. 
MENDEL’S PRINCIPLES APPLIED TO ORCHID HYBRIDS. 
(Continued from page 74.) 
Last month we referred to a very interesting paper with the above title, by 
Captain C. C. Hurst, F.L.S. (Journ. R.H.S., xxvii, pp. 614-624), and 
reproduced the remarkable series of varieties of Paphiopedilum X Hera 
with which it was illustrated (pp. 71-74, figs. 16-18), but a summary of 
the conclusions arrived at had to be deferred till the present issue. 
At the outset Mendel’s theory is briefly described, as follows :—‘‘ That 
determinants of each single character in the germ cells of hybrids (both 
pollen and egg cells) are pure and not hybrid in their nature: representing 
alternatively the respective character either of the one parent or the other 
of the hybrid, but not both.” 
An illustration is drawn from Paphiopedilum xX Leeanum, produced by 
intercrossing P. Spicerianum and P. insigne:—‘‘ According to Mendel’s 
theory, the germ cells of P. x Leeanum will not contain hybrid deter- 
minants for any single character, but one germ cell will contain deter- 
minants of pure P. Spicerianum for that character, while another germ cell 
will contain determinants of pure P. insigne for that same character; the 
process being apparently according to the law of chance. Of course, when 
all the single characters are taken into account together, each germ cell 
would naturally contain determinants of both P. Spicerianum and P. 
insigne, but according to Mendel’s theory there would be no determinants. 
of the hybrid P. x Leeanum itself.” 
Mendel’s theory of the purity of the determinants can only be tested by 
experiment, either (a) by self-fertilisation of the first crosses, or (b) by 
re-crossing the latter with one or the other of their own parents, or (c) with 
another species. - All three experiments have been made, but only the 
results of the third experiment (P. x Leeanum X Boxallii) are at present 
available. The details and figures were given last month, and now we 
must briefly point out the conclusions arrived at. 
The analysis made is confined to the colour of the dorsal sepal, this 
apparently being the most conspicuous character, and probably one of the 
most useful from a horticultural standpoint. This was at first considered 
to be a single Mendelian character, but afterwards regarded as a 
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