PART III. | THE MECHANISMS OF FLOWERS. 421 
for them that several of these bees (Osmia adunca and O. cemen- 
taria) resort to it exclusively, both for their own food and for that 
of their larvae. Syrphide also make frequent use of the pollen, 
while bees with tibial or femoral collecting-baskets seldom gather 
it, and all other insects come solely for the sake of honey. The 
power of self-fertilisation has been completely lost. 
This plant is gynodicecious. The female flowers differ from the 
hermaphrodite in having a much smaller corolla and shorter pistil ; 
their stamens are short, and the anthers contain no sound pollen- 
grains (Darwin, 167). 
Cerinthe glabra, Mill. (C. alpina, Kit.)—This flower is adapted 
for humble-bees. Only humble-bees or other large bees can cling 
Fic. 142.—Cerinthe glabra, Mill. 
A.—Flower that has recently expanded. 
B.—Ditto, in section (x 4). 
C.—Older, fully expanded flower (x 7). 
8. Sepal; co, corolla; n, nectary; ov ovary; gr, style; ji, filament. 
(Falo Alp, July 28, 1877).: 
| to the recurved teeth of the corolla, and hanging beneath the 
flower, suck the honey from its base. In doing this the insect 
_ first brings its head in contact with the stigma, and then, touching 
_ the anthers with its proboscis, it dusts its head with new pollen. 
| LT have only found humble-bees (Bombus alticola, ? 9), but those in 
