102 
THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
small larvte), if any gentleman should 
have more than he wants for himself I 
should be happy to hear from him, and 
will gladly pay postage: — 
Smerinthus Ocellatus, 
... Populi, 
... Tiliae, 
Sphinx Ligustri, 
Chaerocampa Elpenor. 
If I can possibly make any return at the 
end of the season I shall be happy to do 
so. — F. N. Mills, 2 , Arboretum Terrace, 
Osmaston Road, Derby ; June 24. 
Coleoptera offered gratuitously. — Du- 
plicate specimens of Dasyles viridis will 
be sent to any entomologist needing 
them, on receipt of a box and stamp lor 
postage. — C. O. Groom, Hova Villas, 
Brighton. 
ON THE FERTILIZ.4TION OF BRITISH 
ORCHIDS BV INSECT AGENCY. 
BY C. DARWIN, ESQ., F.R.S. 
{Reprinted from the ‘ Gardener's Chronicle’ of 
June 9, I860.) 
(Continued from p. 04.) 
We may now turn to the genus 
Ophrys ; in the Fly Orchis {Ophrys 
musci/era), the pollen-masses, furnished 
with sticky glands, do not naturally fall 
out of their pouches, nor can they be 
shaken out ; so that insect agency is 
necessary, as with the species of the 
other genera, for their fertilization. But 
insects here do their work far less 
effectually than with common Orchids ; 
during several years previous to 1858 
I kept a record of the state of the pollen- 
masses in well-opened flowers of those 
plants which I examined, and out of one 
hundred and two flowers I found either 
one or both pollen-masses removed in 
only thirteen flowers. But in 1858 I 
found seventeen plants growing near 
each other and bearing fifty-seven flowers, 
and of these thirty flowers had one or 
both pollen-masses removed ; and as all 
the remaining twenty-seven flowers were 
the upper and younger flowers they pro- 
bably would subsequently have had most 
of their pollen-masses removed, and thus 
have been fertilized. I should much 
like to hear how the case stands with the 
Fly Orchis in other districts ; for it 
seems a strange fact that a plant should 
grow pretty well, as it does in this part 
of Kent, and yet during several years 
seldom be fertilized. 
We now come to the Bee Orchis 
{Ophrys apifera), which presents a very 
difl'ereiit case ; the pollen-masses are 
furnished with sticky glands, but dif- 
ferently from those in all the foregoing 
Orchids, they naturally fall out of their 
pouches ; and from being of the proper 
length, though still retained at the 
gland-end, they fall on the stigmatic 
surface, and the plant is thus self- 
fertilized. During several years I have 
examined many flowers, and never in a 
single instance found even one of the 
pollen-masses carried away by insects, or 
ever saw the flower’s own pollen-masses 
fail to fall on the stigma. Robert Brown 
consequently believed that the visits of 
insects would be injurious to the fertiliza- 
tion of this Orchis, and rather fancifully 
imagined that the flower resembled a bee 
in order to deter their visits. We must 
admit that the natural fiilling out of the 
pollen-masses of this Orchis is a special 
contrivance for its self-fertilization, and, 
as far as my experience goes, a perfectly 
successful contrivance, for I have always 
found this plant self-fertilized; neverthe- 
less a long course of observation has 
made me greatly doubt whether the 
