94 THE STORY OF THE PLANTS. 



yellow sepals. Moreover, as the marsh-marigold 

 is such a large and handsome flower, it easily at- 

 tracts insects in early spring ; and this has enabled 

 it to effect an economy in the matter of its carpels 

 or female organs. In the buttercups, we saw, 

 these were very numerous, and each contained 

 only one seed ; in the marsh-marigold, on the 

 other hand, they are reduced to five or ten, but 

 each contains a large number of seeds. This 

 arrangement enables a few acts of fertilisation 

 to suffice for the whole flower. You will there- 

 fore find as a rule that advanced types of flowers 

 have very few carpels — sometimes only one — and 

 that when they are more numerous they are often 

 combined into a single ovary, with one sensitive 

 surface, so that one fertilisation is enough for the 

 whole of them. 



Three familiar but highly-advanced members 

 of the buttercup group will serve to show the im- 

 mense changes effected in this respect by special 

 insect fertilisation. They are the columbine, the 

 larkspur, and the monkshood. In the simple but- 

 tercups, the honey, we saw, was easily acces- 

 sible to many small insects; but in the winter 

 aconite it was made more secure by being kept, 

 as it were, in a sort of deep jar ; and in these high- 

 est of the family it is still further hidden away, in 

 special nooks and recesses, like vases or pitchers, 

 so as to be only procurable by bees and butter- 

 flies. These higher insects, on the other hand, 

 are the safest fertilisers, because they have legs 

 and a proboscis exactly adapted to the work they 

 are meant for; and they have also as a rule a 

 taste for red, blue, and purple flowers, rather 

 than for simple white or yellow ones. Hence 

 the blossoms that specially lay themselves out 



