S6 COLIN CLOUTS CALENDAR. 



calyx was practically gone, and in its place a number of 

 bracts were produced as an involucre around the entire 

 head, subserving the same function for the compound 

 blossom as the calyx once subserved for each of its 

 component members. 



Under such circumstances, one of two things must 

 needs happen : either the calyx must become obsolete 

 through disuse or must be preserved by adapting itself 

 to a new function. In the dai.sy, the first result has 

 come about : in the dandelion, the second. The calyx 

 here has grown small and hair-like, and acts as a sail or 

 wing for the light little fruit. Thus the wind catches 

 the seeds when ripe and carries them away to every part 

 of the field. In the simpler plants of the dandelion kind 

 there are only a few of these silky hairs .seated perpen- 

 dicularly on the summit of the fruit, and the subsidiary 

 devices for dispersion arc far less perfect. But in the 

 dandelion itself, which is a very highly adapted type — 

 all these common weeds always arc, and that is what 

 makes them so common — the top of the fruit grows out 

 into a long beak, on which the hairs spread laterally in 

 a circle, so as to present the largest possible surface to 

 the favouring bree/e. Even in the dandelion, however, 

 the hairs themselves arc .straight and simple ; in its near 

 relative, John-go-to-bed-at-noon, the hairs are much 

 longer, and arc subdivided into feathery branches on 

 either side, which make an interlacing parachute even 

 better adapted for driving before the wind than that of 

 its more familiar kinsmen. 



The reason why plants take all this trouble to get 

 their seeds dispersed is a simple one ; and yet it might 

 not immediately strike everybody. Why should the}- 



