THE ORCHID REVIEW. 365 
way A 2 ands 2 are branches of the cord which feeds one lateral sepal, 
while A 3 and s 3 are similarly derived from the other. The cords marked 
a1and a 2 (the fertile stamens of Cypripedium, and the column-wings of 
many other Orchids) are branches from the left-hand and right-hand petals, 
respectively, while a 3 comes from the group which feeds the lip. 
We may now trace the manner in which these several organs are 
combined. The three sepals and two lateral petals call for no remark, but 
coming to the median petal we find that two stamens of the outer whorl 
(A 2 and A 3) are united with it to form the lip, which is thus a compound 
organ, consisting of one petal and two petaloid staminodes. The seven 
remaining organs (the three stamens of the inner whorl, together with A 1 
and the three stigmas) unite to form the central column. Of these, A 1 (the 
median stamen of the outer whorl) is the single fertile anther of the sub- 
order Monandre. In the small suborder Diandre it is also present as a 
perfect anther in Neuwiedia, but modified into a shield-shaped staminode 
in Cypripedium and Selenipedium, and into a linear staminode in Apostasia, 
while in Adactylus it is entirely suppressed. The two lateral stamens of 
the inner whorl are uniformly present as perfect anthers in the suborder 
Diandre, but in Monandre they form the teeth or wings of the column. 
The median stamen of the inner whorl, a 3, forms the front of the column, 
or in some cases is entirely suppressed. Of the three stigmatic 
lobes, s 2 and s 3 are generally confluent into a single stigma, though 
occasionally free, as in some Habenarias and Neottiee, while throughout 
the Monandre (except in the degraded Cephalanthera) s 3 is modified into 
the rostellum, which secretes a viscid fluid for the purpose of attaching the 
pollinia to the bodies of insects which visit the flowers, and also serves to 
prevent the pollen from falling on to the stigma of the same flower. This 
organ is not found in the Diandrz. In the tribe Apostasiez the three lobes 
are simply confluent into a slightly three-lobed stigma, while in Cypripediee 
this organ is composed of s 2 and s 3, s 1 being suppressed. 
The way these progressive modifications have been effected is readily 
seen. In the ancestral group Apostasiee the whole structure is very 
simple. The three stigmas are simply confluent, the anthers are linear, 
and the pollen dry, while the lip simply consists of the median petal, with- 
out the addition of the staminodes A 2 and A 3. Neuweidia has slender 
filaments, which are only united with the style at the base into a very short 
column, while the anthers are versatile, like those of some liliaceous plant. 
The three stamens are the median one of the outer whorl, and the lateral 
ones of the inner whorl (A 1, a 1 and a 2), all on the back of the flower, 
while the three remaining stamens, A 2, A 3, and a 3 are simply suppresed. 
“In Apostasia A 1 is reduced to a linear staminode, adnate to the style, and 
in Adactylus it disappears altogether. In Cypripediew A 2 and A 3 (which 
had become lost) re-appear, but in the guise of staminodes, and confluent 
