of Westralian Plants. 223 
As it is closely allied to Caladenia Barbarossae , and is, I believe, 
pollinated by Hymenoptera, I will include a brief account of it here. Near 
York D.ciliata, Reichb., is plentiful. It grows round the edges of shelving 
granite outcrops where the soil is almost swampy during winter. It 
flowers in November, when the soil is very dry and warm, its fleshy scape 
dying from below upwards as flowering proceeds. D. elastica , Lindl., and 
its near ally D. Glyptodon , R. D. Fitz., occur sparingly on sand. Both 
flower in September. I have not observed the process of pollination in 
any of these species; but after careful and prolonged study of the flowers 
I have formed an idea of the mode of operation of the flower parts. The 
labellum, which in all three sp'ecies is strongly suggestive of some weird 
insect perched upon the blossom, is thinly clothed with shaggy hairs, and 
is attached by a loose but tough hinge. In none of these species is there 
any trace of irritability in any part of the flower. The basal calli bear 
crystalline nectar. My conclusion is that when an insect settles on 
a labellum it is allowed a meal in peace; but when it seeks to leave, its 
legs being somewhat entangled by the shaggy hairs, it is temporarily 
attached to the labellum, and so is constrained to fly in an arc which 
quickly brings it into forcible contact with the stigma, where it soon 
manages to free itself; but not without removing pollen or pollinating 
the stigma. In the case of D. ciliata I actually induced a small hymenopt 
to perform part of the operation ; but it was evidently not the proper 
pollinator. 
The petaloid calyx of Thomasia Montana, Steud., simulates the corolla 
of a Solanum. It is usually of a delicate bluish pink hue, though sometimes 
clear rose. The petals are tiny black scales and seem functionless. The 
stamen bases are connate, forming a shallow cup (this structure is peculiar 
to the species) on whose rim the horny anthers are almost sessile. These 
anthers stand close together and form a black cone from whose apex the 
slender style protrudes. The stamen cup contains thick nectar, to obtain 
which an insect must probe between anther tips and style. That done 
a further obstruction is met: the staminodes, which alternate with the fertile 
stamens, lean inwards and form a tangle round the style. Altogether a deal 
of poking is necessary before nectar is secured. This disturbs the anthers 
and dry, dusty pollen is shaken from their terminal pores. I have never 
seen an insect seek nectar, but I have seen small black indigenous bees 
gathering pollen from the flowers. They perched inverted (the flowers are 
pendulous) upon the anther cones, and agitating the anthers with their legs 
caused pollen to fall out. I concluded that they would effect pollination 
whilst so engaged. They are very active creatures, frequently flitting from 
shrub to shrub. True xenogamy is probably the rule when they act as 
pollinators. The flowers are, however, fertile with pollen from others 
of the same shrub. Some years ago I observed that a solitary shrub, 
