90 -THE FERTILISATION OF FLOWERS. [PART III. , 
Magnolia grandiflora, L.—Rose-beetles (Cetonia aurata and 
stictica) resort to the scarce opened flowers. They find shelter 
beneath the three inner petals, which form a vault over the stigmas, 
warmth which is so considerable that it is sensible to the touch, 
and honey lying on and between the stigmas. They remain in this 
pleasant refuge, until the sepals or petals fall off, and then, laden 
with pollen, they fly away to other flowers. In the first period only 
stigmas, and in the second only anthers, are mature, so selffer- 
tilisation is impossible, and the beetles, flying from flower to flower, 
accomplish cross-fertilisation regularly (178, 360, p. 594). 
Orpd. ANONACE &. 
Asimina triloba, Dunab., is proterogynous with short-lived 
stigmas. In the middle of the bell-shaped, pendulous flower 
rises a hemispherical mass of stamens, from the midst of which 
some stigmas protrude. The three inner petals, which secrete 
honey at their base, lie in the first period close upon the stamens ; 
they compel the flies which visit the flower to touch the already — 
mature stigmas on their way to the honey. Cross-fertilisation is 
effected if the flies come bringing pollen from an older flower. 
Delpino counted seven species of Diptera visiting the plant 
(178, p. 231; 360, p. 672). 
Orv. BERBERIDEL. 
18. BERBERIS VULGARIS, L._—Sprengel describes and figures the 
flowers as hanging down vertically. This, however, is seldom the. 
case ; most are horizontal or inclined obliquely downwards. They 
are not fully protected by their position from the weather, but the 
three inner sepals and the six petals, which as well as the sepals 
are curled inwards at their points, protect the stamens together 
with the honey-glands and honey from rain. The three inner 
sepals make the flower conspicuous by their yellow colour, and 
the petals completely embrace the stamens so long as the latter 
are undisturbed. The honey-glands are two thick, oval, fleshy, 
orange bodies, lying quite close together on the inner side and 
near the base of each petal. The filaments are so much expanded 
as to touch each other at the base; before being irritated they are 
bent so far back that each is in contact with the part of a petal 
below the honey-glands, and also with the adjacent halves of the 
two honey-glands. There is thus no room for the honey to 
accumulate between petals and stamens, but it must flow into 
