EARLY SUMMER FLOWERS 193 



the stem. Alternating with the sepals are five white petals, the 

 main veins of which, converging towards the base, are of a 

 greenish yellow tint. When the sepals and petals are removed 

 ten stamens will be visible, five of which stand slightly farther 

 out than the other five. It is remarkable that the five outer 

 ones are those standing opposite to the petals. The anthers 

 on opening expose the yellow pollen. In the centre of the 

 flower are two styles, which join together lower down. On 

 cutting a flower in half, so as to cut through both the 

 carpels, it will be found (Fig. 88) that the greater part of 

 the ovary, formed of the two united carpels, is enclosed within 

 the expansion of the floral receptacle noticed from the outside 

 of the flower. The upper parts of the two carpels separate 

 and form the styles, which taper some- 

 what till they end in the enlarged 

 stigmas. 



If a number of flowers of different 

 ages are examined the order in which 

 the stamens and stigmas mature will be 

 ascertained and the way in which the 

 flower is pollinated can be understood. Fia gs. Flower of the White 



When a flower Opens none of the Meadow Saxifrage cut in half 



stamens have shed their pollen, and the m the plane of the two car- 



pels. (After Baillon.) 



styles are short and stand close together 



in the centre of the flower ; their stigmas are still immature. 

 The stamens of the inner whorl mature first, and as they open 

 their anthers bend inwards and stand immediately above the 

 pistil. As the pollen is shed these stamens gradually bend away 

 from the centre of the flower. The anthers of the outer whorl 

 of stamens next take up this position and open. The opening 

 of the anthers and shedding of the pollen takes two or three days, 

 and during this period the styles with the undeveloped stigmas 

 remain close together. Then the styles elongate and diverge 

 from one another, and the expanded stigmas develop. The flower 

 thus passes through a stage in which it is shedding pollen, but 

 has immature stigmas, to a stage in which the pollen is all shed, 

 but the stigmas are mature and ready to receive pollen. 



The conspicuous flowers are visited by flies and small bees, 



VOL. III. 13 



