Sunshine, Rain, and Wind 



the season becomes cold and wet, these flowers become 

 smaller and have fewer stamens and carpels. 



An enormous amount of labour has been spent in 

 counting (like Marguerite) the number of ray florets 

 of asters, sunflowers, chrysanthemums, and other Com- 

 positae. Such flowers are, of course, really heads of 

 florets, and might be compared to contracted or fore- 

 shortened inflorescences. These outside ray florets 

 must, one would think, be in some way connected with 

 the arrangement of the leaves on an ordinary stem 

 (see p. 121). 



We would expect then to find the same numbers as 

 occur in leaf arrangement reappearing in these ray 

 florets, and that is found to be the case. 



The commonest or most fashionable number of ray 

 florets (that is, the mode) is generally one or other of 

 the series 5, 8, 13, 21, 34, 55, &c. 23 



In the annual sunflower the mode is 34 or 55, but if 

 such plants are badly treated they will have as a rule 

 only 21 or even only 13 rays. If well supplied with 

 artificial food or manure they may have 89 rays. 

 Oxeye daisies and asters, which come out late in the 

 season, have also but few rays. These few cases show 

 how greatly the climate and especially sunshine may 

 affect the vigour of the plant and quite alter the size 

 and number of flowers.* 



Rainfall has also a marked effect and especially on 

 the leaves. In a rainy climate, for instance, smooth 

 glossy leaves like those of rhododendrons and laurels 

 are distinctly useful. The rain dries off them at once. 

 If they remained wet, the conditions for the germination 

 of fungus or algal spores would be much more favour- 

 able. Another interesting point in rain-leaves is the 



* The number of leaves may be also increased as well as their size, after 

 Goebel and Groom. 84 



188 



