aiioi.wiv i;v a CO-OPERATION OF MOVEMENTS. 



:;s., 



Allium Cham" moly (see fig. 311 ') is an example of the plants, in whose flowers 

 autogamy is effected by concurrent movements of the pedicel and the style, the 

 former undergoing inflection, whilst the latter is inclined in the direction of the 



spots whore the pollen has been deposited. The small white Mowers are lifted but 

 a very little way above the ground; at first they Eace the sky, and are half bidden 

 amongst the long green ribbon-shaped foliage haves. Nevertheless, they are 

 assiduously sought out by small insects, the honey, which is secreted in little depres- 

 sions on the surface of the ovary, being in great request. During the first stage of 

 flowering cross-pollination alone is possible; the stigma is posted in the middle of 



Fig. 310.— Autogamy resulting from an inflection of the pedicel accompanied by spiral torsion of tin- uluinents: Cohmi 



scandens. 



i Side view of a newly opened flower. -, 3 . * Blowers in the three successive stages of their development which lead to 



autogamy. All the figs, somewhat reduced. 



the mouth of the flower, and its tissue is already receptive whilst the anthers are 



still closed and appressed to the walls of the perianth (see tig. 311 2 ). Later on all 



the filaments undergo inclination towards the middle of the flower; the anthers 



burst open, become covered all over with the pollen which issues from their loculi, 



and together form a yellow knob which occupies the centre of the entrance to the 



Ulterior of the flower, and is brushed by all intruding insects. The .stigma is at that 



stage hidden behind the anthers (see fig. 311 3 ), and is not touched by insects. If, 



for any reason whatever, insects do not visit a flower, autogamy takes place in the 



third stage of its development. The pedicel curves over downwards and presses the 



flower against the ground, and, as a consequence, the delicate white perianth-leaves 



and filiform stamens are displaced, and some of the pollen falls out of the anthers 



on to the lower perianth-leaves now resting upon the ground. The style undergoes 



alight lateral. ;., . in these circumstances downward, inclination and the final result 



of all the..,- movements is that the stigma is brought into contact either with the 

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