468 THE FERTILISATION OF FLOWERS. [PART III, 
Morren supposed that the pollen fell of itself from the anthers, 
and either came directly, or was carried by small insects, to the 
hairs upon the inferior wall of the corolla in the neighbourhood of 
the stigma; and that thus, when by any cause the style was 
irritated, the stigma curved over and applied itself to the pollen. 
Acanthus mollis, L., and A. spinosus, L.—The four unilocular 
anthers lie close together and hold between them the loose pollen. 
The inferior filaments pass below and in front of the anthers, and 
are suddenly bent back towards them immediately below their 
attachment. The bee-visitors (Bombus italicus and B. terrestris) 
have to pass between these inferior filaments, and in doing so force 
both them and their anthers apart, and cause the pollen to fall out. 
The proterandrous condition lasts for several days, and then the 
end of the style, which was straight before, bends downwards and 
forwards, so that the lobes of the stigma come in contact with the 
bee (172, 178, 360). 
Aphelandra pectinata, Willd. (A. cristata, H. B. and Kth).—The 
two lobes of the corolla which form the upper lip are rolled round, — 
the anthers; the two lateral lobes are approximated, forming 
folding doors which close the entrance of the tube. When these © 
doors are opened they cause the lobes of the upper lip also to © 
separate, and the anthers are set free and shed their pollen on the © 
visitor. The fertilising-agents are probably humming-birds (178). | 
Rhinacanthus communis, Nees., is markedly proterandrous. In 
the first stage, the two anthers are bent down into the entrance of 
the flower, and the still immature stigma is bent upwards; in the 
second stage the anthers are bent apart to the sides, and the ripe 
stigma is placed exactly in the path of the insect’s proboscis, The 
visitors are probably Lepidoptera (177). 
Orv. SELAGINEA (GLOBULARIACE). 
Globularia vulgaris, L., is proterandrous; G. cordifolia, L., and 
G¢. nudicaulis, L., are proterogynous with persistent stigmas. The 
flowers of all three are light-blue and adapted for fertilisation by 
butterflies. This is the only instance in the German and Swiss 
flora of a blue colour being produced by the selective agency of 
Lepidoptera (609). 
