4 8 NATURE STUDIES. 



these petals showed a tendency to coalesce, and as 

 this tendency proved useful to the plant, by more 

 certainly securing its fertilisation by insects, it rapidly 

 grew through survival of the fittest into a fixed habit, 

 not only of the daisy, but of all the great group of 

 flowers to which it belongs. The reason why the 

 tubular shape is more useful than the arrangement 

 with five spreading petals becomes clear enough if we 

 recollect that the insect has to thrust its proboscis 

 down to the bottom of the tube, past the pollen - 

 bearing stamens and the sensitive pistil, in order to- 

 reach the tiny drop of honey concealed within. In 

 doing so, a little of the pollen naturally adheres to his 

 proboscis, and is then brushed off against the sensi- 

 tive surface of the next blossom which he visits, so a* 

 thus to impregnate and fertilise its seed. To this 

 day, however, the daisy still retains a reminiscence of 

 the distant period when it possessed five separate 

 petals ; for each of the central florets has a van dyked 

 edge of five points, these points being the last repre- 

 sentatives of the original distinct flower leaves in its 

 remote progenitors. 



The tubular arrangement is common to many 

 flowers besides the daisy family ; but the daisies and 

 their allies have carried their development one step 

 further than the rest, for they have learnt to collect 

 several tiny blossoms together into a single compact 

 head, and thus to bid for the attention of insects far 

 more powerfully than they could do in single display. 

 More than that, in the daisy itself, and one or two 



