Scrophulariaceae. 411 



corolla, which like the calyx, is densely covered with glandular 

 hairs, is increased by the faet that the subtending bracts 

 are also of a dull violet. I have not noticed any scent, but 

 honey is secreted by the greenish nectary on the front of the 

 ovary (Fig. 16, G). Muller has described how humble-bees 

 and other insects, by thrusting their proboscis and also their 

 heads into the flower (see Fig. /, the corolla seen from the 

 front) strike against the pointed lower ends of the anthers 

 (Fig. 16, K and L), whereby the anthers which adhere by 

 their hairs, are violently torn from one another, by which 

 means the dry and light pollen-grains are scattered and fall 

 upon the insect, which then easily conveys them to another 

 flower and deposits them upon the stigma (Fig. 16, A — £, M) 

 which protrudes even in the bud (Fig. 16, B). Specimens with 

 flowers, the structure of which is exactly like that of the 

 flowers of the Alps, have also been found to occur both in 

 Norway and in Greenland^, these specimens have evidently 

 marked insect-visited flowers which either cannot pollinate 

 themselves, or can only do so with great difficulty. My figures 

 (which have all been drawn from full-grown flowers) show 

 that both the length of the style and the size of the whole 

 flower vary considerably, apart from the difference of age. 

 Thus specimens are found which have so short a style through- 

 out their whole life, that the stigma does not become visible 

 outside the corolla; in some, however, the stigma is situated 

 immediately inside the throat of the flower (Fig. 16, F^ K)^ 

 but in others it lies even as far inside as above the hind- 

 most anthers (Fig. 16, L). In these cases the stigma lies. 

 against the anthers, and self-pollination, as far as I can see, 

 is inevitable; and in such flowers I have also distinctly seen 



1 Muller does not mention that the style is beset with stiff 

 hairs directed forwards, except at its uppermost end (Fig. 16, H); but 

 it is probable that it has this feature also in the Alps. 



