THE WIND AS CARRIER. 



129 



The common English bur- 

 reed is a waterside plant of 

 great beauty which shows us 

 another interesting instance 

 of wind-fertilisation in an ad- 

 vanced condition (Fig. 28). 

 Here the separate flowers are 

 very much reduced — as sim- 

 ple, in fact, as those of the 

 cuckoo-pint. The males con- 

 sist of nothing but stamens, 

 gathered in close globular 

 heads, with a few small scales 

 interspersed among them, 

 which seem to represent the 

 last relics of a calyx. The 

 females are made up of single 

 ovaries, each surrounded by 

 three or six scales, still form- 

 ing a simple rudimentary ca- 

 lyx. They, too, are clustered 

 in round heads or masses on 

 antler -like branches. The 

 plant belongs to the threefold 

 group, and represents a very 

 degenerate descendant of a 

 primitive ancestor something 

 like the arrowhead already 

 described in the last chapter. 

 But the arrangement of the 

 heads on the stem is very in- 

 teresting. The balls at the 

 top are entireh^ composed of 

 male flowers; those at the 

 bottom are exclusively female. 



Fig. 28. — Flowers of bur- 

 reed. The two lower 

 heads consist of female 

 blossoms, the five upper 

 ones of males. Only 

 one head of the males 

 is mature ; the others 

 are siill in the bud. 



The female flow- 



ers ripen first, and receive pollen by aid of the 



