ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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thickened, the leaves are deformed and thickened, and the inflorescence 
is altogether aborted. Of these plants the peridium and the spermo- 
gones of the parasite develope a honey-like secretion altogether 
resembling that produced in the glands of the normal flowers, 
although, of course, it can have no function either nutritive or for 
attracting insects. It appears to be a means provided for carrying 
out a necessary physiological function of the plant. 
Pollination and Dissemination of [Gymnosperms.* — Prof. F. 
Delpino points out an interesting difference between Ephedra and all 
other genera of Gymnosperms in the structure of the ovule, connected 
with the mode of pollination. In all Gymnosperms the microj)ylar tube 
is filled with a fluid which exudes from its orifice in the form of a drop. 
In all the genera except Ephedra the pollen-grains have a lower specific 
gravity than this fluid ; and in them either the ovules are inverted and 
the inflorescence erect (Abies, Larix , Pinus, Podocarpus), or the ovules 
are erect and the inflorescence pendent ( Cupressus , Biota, Thuja , Taxus, 
Cryptomeria, &c.). In Ephedra alone the pollen-grains have a higher 
specific gravity than the fluid ; and here the ovules and the inflorescence 
are both erect. 
In many monoecious conifers, cross-fertilization is promoted by the 
arrangement of the male and female flowers ; as, e. g. in Cedrus Libanus, 
where the male flowers are usually borne on the lower, the female flowers 
on the upper branches. The dissemination of the seeds of many 
conifers is provided for by their being enveloped in a coloured fleshy 
pulp, which is eaten by birds. The fruit of Ephedra bears a striking 
resemblance to that of Taxus ; but the pulp is not in this instance of the 
nature of an aril, but results from a modification of the uppermost 
bracts of the inflorescence. 
Pollination of the Mistletoe.f — Herr E. Loew throws considerable 
doubt on the statements which are commonly made, that the mistletoe 
is anemophilous, and that pollination takes place in the autumn, the 
pollen-tube penetrating to the neighbourhood of the embryo-sac, but 
impregnation not taking place till the following spring. The following 
facts point almost with certainty to the entomophilous pollination of the 
mistletoe. In the instances observed, the male plants are very much 
less common than the female. Both male and female flowers are fur- 
nished with nectaries, the nectar giving out an odour resembling that of 
orange-flowers, and most powerful in the male flowers. The pollen- 
grains are coherent when fresh, and their extine is furnished with 
minute spines. Both male and female flowers are fully developed in the 
spring, not in the autumn. The author was unable to determine 
what are the visiting insects, but suggests that they are bees belonging 
to the genus Andrcna. 
Fertilization of Bulbophyllum.J — Mr. H. N. Bidley describes the 
mode of pollination in Bulbopliyllum macranthum and some allied 
orchids at Singapore. The sepals exude a sweet substance resembling 
honey-dew, which is eagerly sought by a small dipteron. The feet of this 
* Malpighia, iv. (1890) pp. 3-9. f Bot. Centralbl., xliii. (1890^ pp. 129-32. 
% Ann. of Bot., iv. (1890) pp. 327-36 (1 pi.). 
