Rosaceæ. 97 



warts. Immediately below the anther the filament becomes 

 suddenly thinner. The nearer the stamens approach the 

 centre of the flower, the smaller they are and the more bent 

 inwards; the smallest of all have short much bent filaments 

 the upper thinner part of which is however as long or even 

 longer than that of the outermost stamens (Fig. 37, D, G). 

 As the stamens are so densely and closely united above the 

 centre of the flower it appears as if all smaller and weaker 

 insects must be entirely excluded from access to the honey 

 secreted by the inner side of the hypanthium. I think that 

 only strong insects such as humble-bees and bees will be 

 able to force a way, but perhaps the slender proboscis of the 

 butterfly may discover a way down between the filaments." 

 "Longitudinal sections show moreover that the pistils 

 are lying hidden just below the stamens. The styles, which 

 are slightly thickened towards the apices, are erect, and the 

 irregularly lobed stigmas (Fig. 37, F) are thereby placed 

 immediately below the anthers, and partially even in direct 

 contact with those of the innermost, short stamens. The 

 flowers are slightly protandrous; the outermost stamens 

 open their anthers very early even at the time when the 

 petals still stand almost erect, and before the stigmas are 

 quite mature, though large. But the stigmas evidently be- 

 come functional very quickly after the outermost stamens, 

 because I have seen the stigmas covered with quantities of 

 germinated pollen before the anthers of the innermost sta- 

 mens have opened. Cross-pollination must be possible; but 

 I also believe that pollen must almost certainly fall from 

 the anthers of a flower upon its own stigmas, when an insect 

 thrusts its proboscis down between the stamens, and lhi> 

 evidently happens the more easily because the filaments are 

 rough and must therefore offer more resistance to the intrud- 

 ing proboscis of an insect, and thus be shaken so much 



more effectively. It will (hen depend on whether the pollen 

 xxxvii. 7 



