724 Fluctuations 



buds, branches, and flowers must come under 

 the influence of external conditions during the 

 juvenile period, and so are liable to attain a de- 

 velopment determined in part by the action of 

 these factors. 



Before leaving these general considerations, 

 we must direct our attention to the question of 

 utility. Obviously, fluctuating variability is 

 a very useful contrivance, in many cases at 

 least. It appears all the more so, as its relation 

 to nutrition becomes manifest. Here two as- 

 pects are intimately combined. More nutrient 

 matter produces larger leaves and these are in 

 their turn more fit to profit by the abundance of 

 nourishment. So it is with the number of 

 flowers and flower-groups, and even with the 

 numbers of their constituent organs. Better 

 nourishment produces more of them, and there- 

 by makes the plant adequate to make a 

 fuller use of the available nutrient substances. 

 Without fluctuation such an adjustment would 

 hardly be possible, and from all our notions of 

 usefulness in nature, we therefore must recog- 

 nize the efficiency of this form of variability. 



In other respects the fluctuations often strike 

 us as quite useless or even as injurious. The 

 numbers of stamens, or of carpels are dependent 

 on nutrition, but their fluctuation is not known 

 to have any attraction for the visiting insects. 



