526 THE FERTILISATION OF FLOWERS. [PART IIT. 
379. SALIX REPENS, L.—On the much less conspicuous flowers 
of this small species, 1 found only— 
A. Hymenoptera—(a) Apide: (1) Apis mellifica, L. $, s.,ab.; (2) Bombus 
terrestris, L. 9, ¢.p.; (3) Andrena ventralis, Imh., 9, c.p., 48 .; (4) A. pra- 
tensis, Nyl. 9, cp. ; (5) A. albicans, K. 2, ep. ; 6) A. Gwynana, K. 9,c¢.p.; 
(b) Tenthredinide: (7) Dolerus eglanterie, F.,s. B. Diptera—(8) Bombylius 
major, L., s.; (9) Myopa buccata, L., 8 C. Lepidoptera—(10) Vanessa 
Io, L., s. 
Salix herbacea, L.—Even this, the smallest of our Salices, which 
straggles over the bare rock of the highest Alps, attracts sufficient 
insect-visits to be able to dispense with the possibility of spontaneous 
self-fertilisation ; the latter is rendered impossible by the dicecism 
of the flowers. This fact is strikingly opposed to the common 
statement that on the Alps (owing to the great scarcity of insects) 
only those plants which possess the largest and brightest flowers 
succeed in being fertilised by the aid of insects. The flowers are 
inconspicuous, but the honey is very abundant. The only visitors 
that I have found on the flowers of S. herbacea are a small moth 
(Tineide) and a fly (Cenosia sp.), both sucking honey (609).* 
Orv. HUMPETRACEZ. 
Empetrum nigrum, L., is anemophilous (762). 
Gymnospermee. 
These lowest and oldest Phanerogams have diclinic anemo- 
philous flowers ; the female flowers are devoid of a stigma, and possess 
a cavity in the ovule between the micropyle and the nucleus. In 
the flowering period, a drop of fluid rests upon the micropyle ; the 
pollen-grains brought by the wind are caught by it, and are drawn 
within the micropyle as the fluid evaporates or is absorbed (178 I. ; 
712). 
Delpino has given a fuller account of the process of pollination in 
Pinus pinaster, Ait., and P. halepensis, Ait., (178) and in Larix (177). 
Monocotyledons. 
Orv. HYDROCHARIDEZ. 
Vallisneria spiralis, L.—The male flowers are set free from the 
plant and float on the surface of the water. The pollen, which had 
1 Insect-visitors of Salix fragilis, L., and S. amygdalina, L., are enumerated in 
No. 590, 1. ; and those of 8. reticulata, L., and S. retusa, L., in No. 609. 
