i6o 



DICOTYLEDONS 



fructescence, fig. 201). Pollination. — The honey is secreted 

 along the posterior middle line of the corolla («) by the fleshy 

 part of the base of the tube, and collects there. As the 

 corolla-tube is long, the honey can be fully reached only 



Fig. 200. — Floral diagram of Honey- 

 suckle. 



Fig. 201. — Infruct- 

 escence of Honey- 

 suckle : ^r= bracts ; 

 ex = calyx of each 

 fruit ifiru). 



by insects with very long tongues — that is, solely by butter- 

 flies and moths. The flower is cross-pollinated chiefly by 

 the night-flying hawk-moths. The light colour and sweet 

 scent, especially strong at night time, serve to attract the notice 

 of moths. The position of the stigma obviously renders self- 

 pollination by the flower itself well-nigh impossible. [Endeavour 

 to follow out the dehiscence and movements of the stamens.] 



Types II. and III. : The ELDER {Sambucus nigra) and 

 GUELDER-ROSE ( Viburnum opulus). 



Although the flowers of these two plants are constructed on 

 the same general plan (K5 C5 A5 G(3) ) as those of the Honey- 

 suckle, they differ from the latter very widely as regards their 

 shapes. Their flowers are erect and regular, and their corolla- 

 tubes are very short. Accordingly, we find that their insect- 

 visitors are widely different from those of the Honeysuckle. 

 The honey is freely exposed in the Guelder-Rose, whilst the 

 Elder flowers, though they secrete no honey, are highly-scented, 

 and are visited by insects desiring their pollen. Thus, in both 

 these plants, the insect-food is very easily accessible ; and the 

 chief pollinating agents are short-tongued beetles and flies. 



