VARIOUS MARRIAGE CUSTOMS. 99 



the little store of honey. As he does so, he 

 turns gradually round all over the carpels, and 

 dusts himself with pollen from the ripe stamens. 



And now we must notice another curious 

 device for ensuring cross-fertilisation in many 

 flowers. In the bulbous buttercup the stamens 

 and carpels do not come to maturity together ; 

 the stamens ripen first, and after them the 

 carpels. How does this ensure cross-fertilisa- 

 tion ? Why, if the bee comes to a flower in the 

 first or male stage, in which the stamens are at 

 their full, and discharging pollen, the sensitive 

 surfaces or stigmas of the carpels will yet be 

 immature, so that he cannot fertilise them with 

 pollen from their own blossom. He can only 

 collect there, without disbursing anything. But 

 as soon as he comes to a flower in its second or 

 female stage, with the carpels ripe, and their 

 sensitive surfaces sticky, he will rub off some 

 of the pollen he has thus collected, and so cross- 

 fertilise the flower he is visiting. 



Each buttercup thus goes through two stages. 

 First, its stamens ripen from without inward, 

 till all have shed their pollen and withered. 

 Then the carpels ripen in the same order, till 

 all have been fertilised by the appropriate insect. 

 Each carpel here contains a single seed, which 

 begins to swell as soon as the ovary is impreg- 

 nated. 



We may take it that some such flower as that 

 of the bulbous buttercup represents the original 

 ancestor of all the buttercup group, from which 

 other kinds have varied in many directions. 

 Omitting for the present all questions as to tlie 



