382 THE FERTILISATION OF FLOWERS. [PART III. 
Only here and there are anthers found to have escaped from their 
pouches (Professor W. J. Beal, No. 41, and J. T. Rothrock, No. 
676). 
Rhododendron ferrugineum, L., was found by Ricca to be 
proterandrous, and visited by humble-bees at a height of over 
7,000 feet (665). The position of the honey causes an insect- 
visitor to pass towards it by way of the upper half of the horizontal 
flower, and as the stamens and style curve upwards, they come in 
contact with the ventral surface of the insect. In the first stage 
the style is shorter than the stamens and the stigma is immature ; 
the anthers dehisce apically by means of two orifices. Afterwards 
when the pollen has usually been all carried away, the style elongates 
to its full length and the stigma attains its full development; but 
the latter is still slightly overtopped and almost touched by the 
tallest anthers, and in absence of insects it must frequently come 
in contact with the pollen. Whether such self-fertilisation is effective 
is unknown (6090). 
Rhododendron Rhodore, Don. (Rhodora canadensis, L.)—The 
floral mechanism is described by Hildebrand (367). 
Tribe Pyrolee. 
Pyrola uniflora, L., and P. rotundifolia, L.—These species are 
probably cross-fertilised by short-lipped insects, which may be seen’ 
applying their mouths to the moist stigma and the orifices of the 
anthers. I have directly observed cross-fertilisation performed in 
this way in the case of Pyrola minor, L. (No. 609, figs. 149, 150). 
Eugene Warming found flowers of different forms and sizes on 
P. minor. He observed a plentiful secretion of honey in the case © 
of P. secunda (762). ae . 
Orv. EPACRIDEA. | 
Lpacris.—Delpino found one species to be proterogynous (178). 
Orv. PLUMBAGINE &. 
Some Brazilian species of Plwmbago and Statice are dimorphic, 
according to Fritz Miiller (550). 
Armeria, according to Treviranus, is self-fertilising. As the 
anthers dehisce, the filaments curve inwards, bringing the anthers 
immediately above the depressed centre of the stigma on which — 
they shed their pollen (742), | 
