Effect of Manures 



upon the localisation of gro'^h. Thus soils rich in 

 combined nitrogen (whether naturally or by the 

 addition of manures) promote the growth of foliage, 

 perhaps at the expense of flowers ; plants growing 

 in soils where available potash is abundant usually 

 store more starch or sugar than where it is only 

 barely sufficient ; while abundant supplies of 

 phosphates appear to encourage flowering, and 

 especially fruit and seed production. These are, 

 however, but examples of the power of response to 

 changes in their surroundings possessed by plants, 

 and might be multiplied almost indefinitely for ea«h 

 variation in all the surroundings which we have 

 considered. 



18 



