LIFE HISTORIES OF FAMILIAR PLANTS 



some of the species are, as it were, struggling to 

 regain their lost ground. 



Then, on the other side, there are the aristo- 

 crats of the Buttercup family ; those genera which 

 have retained and evolved their original parts 

 to a higher degree of perfection. These begin 

 with the Columbine (Aquilegia vulgaris) which 

 is commonly cultivated in gardens (Fig. io6, 

 Plate yj). 



The columbine has attained the highly-evolved 

 blue colour, which denotes that it seeks pollination 

 from the higher insects, as bees and butterflies. 

 Its petals have been converted into horn-like 

 spurs, knobbed at their ends, in which honey is 

 stored. Also the five sepals have become coloured 

 like the petals, and are displayed alternately with 

 the open mouths of the five honey tubes of the 

 petals. 



Thus the columbine has evolved its primitive 

 nectaries to a high degree, for now the honey can 

 only be reached by insects that possess a proboscis 

 sufliciently long to reach to the end of the tube. 

 The stamens and stigmas project from the centre 

 of the flower and serve as a landing-stage for the 

 fertilising insects (Fig. io6, Plate yj). Its stamens 

 come to maturity first, so that their pollen is 

 removed by the body and the legs of the bee as it 

 turns about to search each of the five honey- 

 bearing petals, and is then carried to older flowers 

 whose stigmas have ripened ; thus cross-fertili- 

 sation is effected. The ovaries number only five, 

 and each one contains several seeds — another sign 



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