300 THE FERTILISATION OF FLOWERS. [parr mt. 
Orv. RUBIACE 4. 
205. Gatrum Mot.uco, L.—A fleshy disk lying upon the ova: 
and surrounding the base of the style secretes honey, but in s ch 
small amount that it remains adhering in a very thin layer to a 
disk. In young flowers (Fig. 104, 1) the anthers stand erect and are 
covered all round with pollen, while the two stigmas as ie lie 
close together. Afterwards the stamens spread out horizonta. 
and finally their ends curve downwards between the petals outside 
the flower, while at the same time the two styles diverge (Fig. 104, 2 : 
The stigmatic papillae seem to be as well developed in the fi st 
period as in the second, and are not unfrequently covered witl 
pollen while the stigmas still stand close together. The movement 
Fic. 104.—Galium Mollugo, L. 
1.—Young flower, with stamens and styles erect. 
2—Older ditto. The stamens are bent out of the flower, and the styles have sa 
8.—Centre of the flower, from above, more magnified. 
a, two stigmas ; b, fleshy disk above the ovary. 
of the stamens seems therefore not to be accompanied by dichog am i 
but to be the sole contrivance to prevent self-fertilisation and, 
case of insect-visits, to insure cross-fertilisation. 7 
The thin layer of honey can scarcely tempt long-tongued ins 
to repeated visits. The colour of the flowers oe llowishamal in 
the bud and in the young flower, becoming purer white afterwards, 
—seems to repel all those insects, e.g. beetles, which are only 
attracted by bright colours. In this relation a comparison of t 
insect-visitors of G. Mollugo and G. verwm is instructive. a 
In this and the following species of Galiwm the pollen is con- 
veyed to the stigma chiefly by the feet and, in a less degree, by by 
the proboscides of insects creeping over the inflorescence, ao 
Visitors : A. Diptera—(a) Stratiomyide : (1) Odontomyia viridula, F., Lh, 
not rare ; (b) Bombylide: (2) Anthrax flava, Hffs. (Thur.), do. ; (8) Syste- 
chus sulfureus, Mik. (Thur., Sld.), s., probably boring into the nectary ; (c ) 
Syrphide ; (4) Syritta pipiens, L., ab., s. and f.p.; (5) Syrphus ribesii, L., 8 
