Bulbophyllum macranthum , , and allied Orchids. 331 
were at work upon the smaller flowers and were jostling each 
other in close proximity to the lip. This saving of time is of 
considerable importance. The flowers only last two days at 
the outside, and a heavy shower of rain may come at any 
minute and spoil them. Besides, the mechanism of the lip is 
liable to get out of order, and it will not move properly after 
the flower has been open some time, if it gets at all dry. 
Although the mechanism is so beautifully arranged it does 
not always succeed. I have seen a fly twice running thrown 
from the lip without striking the pollen-masses. This was 
because it managed to use its wings before it reached the 
column, and so flew off. But it returned each time, until on 
one occasion it was not quick enough and was caught. 
I examined the sepals carefully with the microscope to see 
what it was the flies obtained, and made transverse and longitu- 
dinal sections of the upper portion. The upper surface of the 
sepals is covered with an exceedingly thin layer of delicate, 
rather narrow and elongate cells, quite transparent and appa- 
rently empty. Beneath these is a layer of thicker and broader 
cells full of granular matter, which readily escapes when 
a section is made of the sepals ; below these again is a layer 
of coloured cells. There are no definite saccharine glands ; 
but, as far as I was able to make out, there seems to be an 
exudation of nectar on the surface of the sepals, perhaps 
analogous to honeydew, which seems to come from the 
second layer of cells. I was unable to detect any sweetness 
of taste on the sepals, and they always appear to be quite 
dry. One cannot help being reminded of the shining black 
bosses at the base of the lip in Ophrys muscifera , which has 
been seen (Hermann Muller, Fertilization of Flowers, p. 535) 
to be visited by a species of Dipteron ( Sarcophaga ). And one 
may reasonably doubt whether these and similar bodies are 
really sham nectaries, as Sprengel, Darwin and Muller seem to 
have imagined ; for we have in this Bulbophyllum a flower 
with no visible nectar regularly visited by a species of Dipteron 
only seen besides on two very similarly constructed flowers ; and 
furthermore this insect is evidently not disappointed in its 
