INFLOEESCENCE AND FLOWERS FRUIT AND SEED 123 



number of stamens ; the former are covered with short 

 hairs. 



Each of the stamens consists of a slender thread 

 (filament) bearing on its top a four-chambered swollen 

 anther. This contains a yellow dust, the pollen, com- 

 posed of round grains (pollen grains), each with three 

 thinner spots in its otherwise thick wall. Each of these 

 pollen grains consists of a membrane enclosing nucleated 

 protoplasm and food materials. When ripe the wind 

 blows the pollen as it scatters from the dangling stamens, 

 and some of the grains reach the stigmas of the female 

 flowers ; here they germinate, each pollen grain sending 

 a delicate pollen tube down the style into the ovary of 

 the flower. This process of application of the pollen 

 grains to the stigma is termed pollination, and depends 

 on the wind. 



The female inflorescences are also spikes (fig. 32, A), 

 but they bear only one to five flowers, and stand off front 

 the axils of the foliage leaves. In the commonest English 

 variety (Q. pedunculata) the spikes are rather long, ob- 

 liquely erect, and the flowers are scattered on the upper 

 end of the rachis of the spike ; in other varieties the 

 flowers are more clustered in the axils of the leaves. 

 Here, as in one or two other details, minute differences 

 are apparent in different individuals; similar trifling 

 differences are met with in the structure of the male 

 flowers. 



Each female flower springs (like the male) from the 

 axil of a small bract : in other respects it is very unlike 



