164 SAKOTHAMNUS SCOPAEIUS. CHAP. V. 



with the much elongated curved pistil, spring forth with violence. 

 The flattened, spoon-like extremity of the pistil rests for a time 

 on the back of the bee, and leaves on it the load of pollen with 

 which it is charged. As soon as the bee flies away, the pistil 

 instantly curls round, so that the stigmatic surface is now up- 

 turned and occupies a position, in which it would be rubbed 

 against the abdomen of another bee visiting the same flower. 

 Thus, when the pistil first escapes from the keel, the stigma 

 is rubbed against the back of the bee, dusted with pollen 

 from the longer stamens, either of the same or another flower ; 

 and afterwards against the lower surface of the bee dusted 

 with pollen from the shorter stamens, which is often shed a 

 day or two before that from the longer stamens. * By this 

 mechanism cross-fertilisation is rendered almost inevitable, and 

 we shall immediately see that pollen from a distinct plant is 

 more effective than that from the same flower. I need only add 

 that, according to H. Muller, the flowers do not secrete nectar, 

 and he thinks that bees insert their proboscides only in the hope 

 of finding nectar ; but they act in this manner so frequently and 

 for so long a time that I cannot avoid the belief that they 

 obtain something palatable within the flowers. 



If the visits of bees are prevented, and if the flowers are 

 not dashed by the wind against any object, the keel never 

 opens, so that the stamens and pistil remain enclosed. Plants 

 thus protected yield very few pods in comparison with those 

 produced by neighbouring uncovered bushes, and sometimes 

 none at all. I fertilised a few flowers on a plant growing 

 almost in a state of nature with pollen from another plant 

 close alongside, and the four crossed capsules contained on 

 an average 9'2 seeds. This large number no doubt was due 

 to the bush being covered up, and thus not exhausted by 

 producing many pods ; for fifty pods gathered from an adjoining 

 plant, the flowers of which had been fertilised by the bees, 

 contained an average of only 7' 14 seeds. Ninety-three pods 

 spontaneously self-fertilised on a large bush which had been 

 covered up, but had been much agitated by the wind, contained 

 an average of 2*93 seeds. Ten of -the finest of these ninety- 



* These observations have been ix. 1866, p. 358. H. Muller has 



quoted in an abbreviated form by since published a full and excel- 



the Eev. G. Henslow, in the lent account of the flower in his 



' Journal of Linn. Soc. Bot.' vol. ' Befruchtung,' &c. p. 240. 



