Aucust, 1909.] THE ORCHID REVIEW. 249 
noticed a lot of good D. Phaleznopsis. We also saw examples of Brassa- 
vola Digbyana, and some good Lelia majalis in bud. 
These notes were taken on the occasion of a rather hasty visit, during 
which we saw that Orchids were both extensively and well grown, and 
although the fog fiend makes too frequent incursions into the district during 
the winter, still Mr. Wrigley and his able gardener, Mr. Rogers, can point 
to a great amount of success, and especially in the favourite Cypripedium 
group, which makes such a fine display at Bury during the autumn. 
(To be concluded.) 
THE EVOLUTION OF THE ORCHIDACE. 
(Continued from page 196). 
In our last paper we outlined the characters of the Australasian subtribe 
Diuridez, and before proceeding to the Neottiez it may be interesting to 
mention a few special genera of the former group, some of which show a 
high degree of specialisation in the perianth. The genus Corysanthes may 
be compared with a dwarf Pogonia of the section Nervilia as regards habit 
and the consistence of the pollen, but the perianth is remarkably complex 
Both leaf and flowers are usually solitary, the latter being proportionately 
large, and the lip broadly tubular, with an oblique, fringed or denticulate 
mouth, and situated under the large, hood-shaped dorsal sepal, the lateral] 
sepals and petals being very small. Fitzgerald says that the plants are to 
be found among leaves and sticks, and insects crawling through the mass 
of rotten vegetation may readily enter the funnel-shaped lip. The column 
is short, the pollinia very friable, crumbling at the slightest touch, and the 
viscus from the rostellum copious, but the details of fertilisation do not 
appear to have been made out, though Fitzgerald had little doubt that 
small insects of various kinds crawl into the lip and fertilise the flowers. 
The genus occurs also in New Zealand and Indo-Malaya. 
Pterostylis is a genus of upwards of thirty Australian and New Zealand 
species. The dorsal sepal and petals form a large hood over the column, 
while the lateral sepals reflex underneath. The lip is sensitive, and when 
the flower opens it reflexes over the lateral sepals, forming a landing stage 
in front of the flower. When an insect alights on the lip the latter springs 
up, carrying with it the insect, which is thus imprisoned in a small box, 
from which it can only escape by crawling out between the column wings 
and over the anther, and in doing this it gets smeared with viscid matter 
from the rostellum, to which the pollen masses adhere, and on repeating 
the process on another flower .the pollen grains adhere to the stigma and 
fertilisation is effected. If the insects are excluded seeds are not produced. 
The lips remain closed for some time, and on re-opening is again sensitive 
toa touch. The flowers are frequented by small flies. 
) 
