INTRODUCTION. 7 
with perpetual sterility. It is often deeply channelled, or has 
guiding ridges,’ .... often approaches the other divisions 
‘closely enough to render the flower tubular.” It is properly 
the upper petal, but a slight twist in the ovary or seed-vessel 
has turned the flower upside down, a change enabling insects 
to enter the flower more easily. 
“In most flowers, the stamens, or male organs, surround 
in a ring the female organs, called the pistils. In all common 
Orchids there is only one well-developed stamen, which js con- 
fluent with the pistils and they form together the column. 
Ordinary stamens consist of a filament or supporting thread 
{not always seen in the Orchids) which carries the anther” and 
this is “‘a sort of case filled with a waxy or meal-like powder. 
called the pollen, which serves to fertilize the pistil.” “The 
anther is divided into two cells, which are very distinct in 
most Orchids, and appear in some x 
species like two separate anthers.’’ 7 \ 
“Orchids properly have three pistils 1.3 
united together, the upper and anterior .Y 
surfaces of two of which form the two ” 
stigmas. But the two are often com- * iy 
pletely confluent so as to appear as 
Fic. 2.—SECTION OF THE FLOWER 
one.” The grains of pollen, when de- or an Orcup. (From Darwin ) 
Pe, Pe, Petals ; Se, Se, Se, Sepals ; 
o, 5, Stigmas ; Sy, Stigma mod- 
ified into the rostellum 
A, Fertile anther of the outer 
face, “carry the contents of the grains whorl; 42, 4, anthers of the 
. same whorl combined with the 
down to the young seeds in the ovary,” lower petal, forming the label- 
. . lum; @,, @g, rudimentary an- 
which, when mature, is “a tI-celled, thers of the inner whorl (fertile 
in Cypripedium), generally 
forming the clinandrum; 4s, 
third anther of the same whorl, 
when present, forming the 
“The upper stigma is modified into an front of the column. 
posited on the stigma, “emit long 
tubes,’ and these penetrating the sur- 
3-valved pod, with innumerable minute 
seeds appearing like fine sawdust.” 
extraordinary organ called the rostellum, which in many Or- 
chids presents no resemblance to a true stigma. When mature, 
it either includes or is altogether formed of viscid matter.” 
