SEPfEMBER, 1921.] THE ORCHID REVIEW. 
PHAIUS BLUMEI. 
C HERE is a peculiarity about Phaius Blumei that oftentimes spoils its 
attractiveness, for some of the flowers become self-fertilised before 
they expand. Regarding P. Blumei var. Bernaysii, which has sulphur- 
yellow flowers, Messrs. Veitch state in their Manual“ It is of little value 
as a horticultural plant on account of the flowers being often self-fertilising 
before they expand, and thence lasting but a short time in perfection.” But 
in 3904 the Bernaysii variety flowered well in the Kew collection, all the 
blooms opened perfectly, so this peculiarity is by no means certain. 
Gleistogamous, or self-fertilising, flowers may be regarded as arrested 
formations, in which, however, the sexual organs reach maturity. 
Further light on the subject is obtained from the observations of Mr. 
H. O. Forbes {Jnr. Linn. Soc. XXI. p. 538), who spent some time on the 
West Javan hills, where he had execellent opportunities for studying the 
fertilization of the Orchids growing in the vicinity. Of Phaius Blumei he 
examined more than 150 flowers, but did not find one that was not self- 
fertilized. They were found in two forms, slightly but interestingly different. 
In the one, the rostellum was a well developed projection ; in the other, of 
which there were many more examples, there was no rostellum, although 
the boundaries of the stigma were quite distinct. 
Regarding the first form, that having the rostellum, Mr. Forbes states 
“ On examining an advanced bud, the viscid matter of the stigma is seen to 
be in large quantity and rather liquid, and as it grows the amount of 
viscid matter becomes greater and greater till it overflows the stigma—often 
before the bud opens; and immediately on its opening inundates the 
pollinia, which now increase in size and emit their tubes over the narrower 
portion of the rostellum into the stylary gland. Very often, however, both 
anther and stigma are quite filled up by the multitude of pollen-tubes and 
by the swollen pollinia. All these plants produced large and well-filled 
seed-capsules on every flower. During all my observations I have never 
Of the second form of flower, in which the rostellum was absent, Mr. 
Forbes remarks :—“ As the flower grows, the anther ruptures and rotates 
forward, and when it has described about 90° it occupies the position 
which, if it possessed a rostellum, it would naturally retain; but having 
none, it continues to rotate through about 70° more till it comes in contact 
with the face of the column, that is with the stigmatic cavity, which is full 
of viscid matter. The whole surface of the lower four pollinia come into 
contact with the viscid matter, and sink well into it; and this viscid matter 
finds its way gradually into the whole anther. The inundated pollinia 
have no obstacles to bar the way of their tubes to the ovary. When 
