FERTILISATION OF SOME AUSTRALIAN PLANTS. 
411 
style. The only means of exit is by climbing to the top, and even if 
there is r.o opening there the insect would go upwards. While on 
the top of the column it is smeared with pollen, and after a time the 
hood slowly drops to its normal position and sets it free. Should 
the insect then visit a flower with a. mature stigma, the same course of 
events happens, and in endeavouring to escape the pollen is smeared 
on the stigma. The insect must be a small one, and probably is 
winged, as the plant is thickly covered with sticky trichomes to prevent 
access of crawling insects. 
ACANTHACE^E. 
Eranthemum var labile, R. Br. — The front petal forms a landing- 
place for insects, and is marked by spots of deep colour as guides to 
the tubular throat of the flower. The stem is' covered with hairs 
pointing downwards, mingled with a few glandular hairs ; the calyx 
is very thickly covered with glandular hairs. After the seeds develop, 
however, these trichomes wither on the part below the fruit, but 
remain plump above it. The tube of the corolla is full of nectar. 
There are 2 anthers which are proterandrous, and 2 staminodes, 
which are very small, entirely hidden in the tube, and, so far as 1 can 
see, bear no part in the process of fertilisation. When the flowers 
first open, the anthers stand close together — almost touching— and 
overhang the mouth of the tube, so that no insect can insert its 
proboscis without rubbing against the pollen. At the same time they 
hide the stigma and prevent its being touched from the front ; at this 
stage the lobes of the stigma are not unfolded. When the anthers 
have shed all their pollen they move apart sideways and slightly 
backwards, and the style then bends forward so as to fill the space 
occupied by the anthers before, and insects visiting the flower must 
of necessity rub against it ; at the same time the stigmatic lobes 
unfold. The plant must be fertilised by insects with a proboscis lono- 
enough to reach the bottom of the tube, and the one most commonly 
doing it is a small day-flying moth. But I have also observed small 
pollen-eating beetles on the flowers, and they may possibly also act as 
fertilisers. It invariably bears seed for every flower. Darwin 
mentions the genus in a list of plants bearing cleistogamous flowers, 
but I have never seen anything of the kind in this species. 
VERBENACEAi. 
Clerodendron iomentosum, R. Br. — In the paper on this plant 
referred to before (4), 1 mentioned the sphinx-moth, Deilephila celerio 
as being the insect which ordinaiily fertilised this plant. But this 
year I have observed Macroglos&a errans, Chcerocampa Oldenlctndice, 
C. Scrofa, Macrosila casuarince, and Proloparce convolvuli in numbers 
round a tree. The latter, however, from its great length of proboscis 
(4| inches in one specimen which I measured), is able to suck up the 
nectar without its body coming into contact with the anthers or 
stigma. All the others carry away pollen on the underside of thorax 
and abdomen. 
ORCHIDE^. 
Dendrobium speciosum , Sm. — Mr. R. D. Fitzgerald (5) says this 
plant is fertilised principally by an insect, Stethopachys formosa, which 
frequents the plants to eat the leaves. But I think the colour of the 
