‘parvu] © THE MECHANISMS OF FLOWERS. 215 
 Galactia, P. Br., and Voandzeia, Pet. Th., are stated by H. v. Mohl 
and Kuhn to possess cleistogamic flowers. 
| Glycine chinensis, Curt., is visited by bees only (590 IL). 
—- Centrosema virginiana and Clitoria mariana both have their 
flowers inverted (729). 
In Erythrina crista-galli, according to Delpino, the flower i is 
inverted, the ale are almost entirely aborted, and the carina forms 
a sheath covering the column and expanded below into a large 
| honey-receptacle. Since the stigma somewhat overtops the 
_ anthers, the visitors, probably humming-birds, touch first the 
_ stigma then the anthers, and so effect cross-fertilisation. In 
| £. velutina the flower is not inverted; the ale and carina are 
_ reduced to minute rudiments, and the column lies fully exposed 
_ beneath the vexillum. The visitors, probably bees, must make their 
| way between the column and the vexillum to reach the honey, 
which is secreted as in other Papilionacee, and so they come in 
contact with the stigma and anthers (178, 360). Belt (56) sawa 
_ species of Erythrina fertilised by humming-birds, which came in 
_ search of small insects that sucked honey in the flowers. Trelease 
saw Lrylhrina herbacea visited abundantly by ruby-throated 
humming-birds, and believes that the flower is adapted for cross- 
fertilisation by their agency (731). 
Darwin states on the authority of MacArthur’s observations 
that, in New South Wales, Erythrina does not produce good fruit 
unless the flowers are shaken (152). 
_ PHASEOLUS.—The species of Phaseolus are distinguished from 
_ the other Papilionaceze which have brush-hairs on the style by 
_ the helicoid twisting of the style and of the tip of the carina 
which incloses it; but here, as in the rest, when the carina is 
__ pressed down, the tip of the style issues with its stigma and pollen- 
_ brush, and these return within the carina when the pressure is 
' removed. The twisting is towards the right in some species and 
_ towards the left in others, according to Delpino, and shows all 
stages from a mere sickle-shaped curvature (P. angulosus, etc.) to a 
helix of four to five coils (P. Caracalla), (172, 178). 
____ The mechanism of the flower and the mode of fertilisation in the 
_ Scarlet Runner (P. coccineus, Lam.) have been thoroughly described 
_ by Mr. T. H. Farrer (240). The hive-bee and other small bees 
| which are unable to press the carina down, obtain the honey by 
taking advantage of holes which a humble-bee (I suppose B. 
|. terrestris, L.) bites through the calyx. More powerful bees, with 
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