Sargent. — Notes on the Life- Hi story of Pterostylis. 267 
a second at its base. True to its ordinal character, the flower develops with 
its face towards the axis of the plant. In most orchids the flower is brought 
face forwards by torsion of the ovary. In Pterostylis the ovary is not 
twisted. In the many-flowered species the stem above the flower’s insertion 
leans to one side, and so leaves the face of the flower free from obstruction. 
The flower usually leans forward and thus appears on the side of the stem 
opposite to that on which it is inserted. 
The flower itself is remarkable and rather complicated. I think its 
structure and mechanism can best be explained by taking the flower of 
P. reflexa as a type, and describing it in detail with the aid of Plate XIX, 
prepared by my friend, Mr. Stanway-Tapp. The anterior sepal (or so-called 
‘ dorsal ’ because it forms the back of the flower) and the petals together form 
a galea, which much resembles a boat placed 6 bows uppermost ’ (Fig. 
and m.s.). The petals are attached to the sepal in a most ingenious way 
(Fig. 6). Each edge of the sepal (j.) is sharply bent inwards, and the tongue 
or flange thus formed fits so tightly into a groove in the petal (p.), that it is 
difficult to separate the parts without tearing. The lateral sepals are united 
for the greater part of their length from the base upwards. Their free 
apices diverge considerably and terminate in long filamentous antennae. It 
will be convenient to have a short, distinctive name for this structure (the 
conjoined lateral sepals), so I will follow the simile of a helmet and call it the 
visor . It stands erect in front of the galea in this species, and thus the lower 
part of the flower is completely closed, the diverging apices of the visor 
leaving the upper part of the galea widely open (Fig. 2). The labellum, always 
an interesting member of an orchid flower, is in this genus specially interest- 
ing. In the species under discussion a short, slightly cuneate, ribbon-like 
claw supports a long lanceolate lamina (Fig. 1, /). At the base of the 
lamina a curious appendage arises. This appendage is a delicate strap of 
tissue ending in a few barbellate hairs. It is doubly curved : first trans- 
versely into a half-cylinder, thus securing rigidity ; and then longitudinally 
so that it forms a semicircle. Its apex points upwards, the terminal 
brush being practically parallel with the face of the lamina (Fig. 8, app.). 
The column (Figs. 4, 5, and 10), which is arched over and completely 
enclosed by the galea, is a slightly curved fleshy pillar. It bears on its face 
about midway between base and apex two slightly sticky oblong cushions, 
the stigmas (Fig. 5). Just above these stigmas two large wings arise, one 
from each side of the column. These may be considered as originally 
rectangular bands of tissue, whose upper front corners have grown out into 
erect horns, and the lower front corners into large rounded lobes. These 
wings are curved, so that their edges almost meet in front of the column 
(Fig. 4). Thus a covered archway is formed in front of the column, the 
lower lobes bending outwards to touch the side of the galea. In this way the 
galea is divided into two chambers, an upper and a lower. The only means 
