A Family History. 207 



boggy species has developed purple petals to meet 

 the aesthetic requirements of the marsh-land . insects. 

 No doubt the white blossoms of the barren straw- 

 berry are thus due to some original ' sport ' or acci- 

 dental variation, which has been perpetuated and 

 become a fixed habit of the plant because it gave it 

 a better and surer chance of setting its seeds, and so 

 of handing down its peculiarities to future genera- 

 tions. 



And now, how did we find the true strawberry 

 had developed from the three-leaved white potentilla ? 

 Here the birds came in to play their part, as the bees 

 and flies had done in producing the white blossom. 

 Birds are largely dependent upon fruits and seeds for 

 their livelihood, and so far as they are concerned it 

 does not matter much to them which they eat. But 

 from the point of view of the plant it matters a great 

 deal. For if a bird eats and digests a seed, then the 

 seed can never grow up to be a young plant ; and it 

 has so far utterly failed of its true purpose. If, how- 

 ever, the fruit has a hard indigestible seed inside it 

 (or, in the case of the strawberry, outside it), the 

 plant is all the better for the fact, since the seed will 

 not be destrpyed by the bird, but will merely be dis- 

 persed by it, and so aided in attaining its proper 

 •growth. Thus, if certain ■ potentillas happened ever 



