LIFE HISTORIES OF FAMILIAR PLANTS 



used for fertilising the stigmas in other flower- 

 heads. In this way not only is cross-fertilisation 

 of the seed-producing ray florets effected, but they 

 are assured of receiving pollen from a distinct 

 flower-head ; and this is as likely as not to be 

 brought from an entirely different plant, which 

 would give still more vigour to the effects of such 

 cross-fertilisation. 



The coltsfoot guards its pollen almost as a bird 

 does its eggs. When at first the flower stem peeps 

 above the soil, its head droops while the stem 

 elongates. Then, suddenly, the head becomes 

 erect and the florets are exposed ; but only in 

 response to an hour of tempting sunshine ; at 

 night, or before if a storm approaches, each flower- 

 head quickly closes. At the time of the year 

 when the coltsfoot shows its flowers it has severely 

 cold nights to contend with, and continually 

 changing weather, together with heavy rains and 

 perhaps snow, and its pollen and maturing seeds 

 take considerable risks. 



Nevertheless, the remote ancestors of the 

 coltsfoot struggled through these trying vicissi- 

 tudes for many ages, from generation to genera- 

 tion, ever adapting their structures, by bitter 

 experience, how best to overcome their greatest 

 difficulties. To-day we find them at a victorious 

 stage of their history ; we see them when they 

 have stolen ahead of many of their keenest 

 competitors, and have become established as a 

 strong and dominant species. So it occurs that 

 in March and April, just when most plants are 



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