PERENNIAL PLANTS. 31 



alone retain comparatively large proportions of phos- 

 phated earth and alkalis, being nothing else than the 

 excess of those substances which the roots do not require 

 for the next year. 



The underground organs of perennial plants are the 

 economic gatherers of all the vital conditions necessary 

 for certain functions. If the soil will allow, they always 

 collect more than they give out ; they never spend all 

 they receive. These plants form their flowers and seeds 

 when the roots have collected a certain excess of phos- 

 phates, which may be given up without endangering 

 the existence of the plant. An abundant supply of 

 nourishment, by means of manuring, will accelerate the 

 developement of the plant in one or another direction. 

 Manuring a sward with ashes will draw from it clover 

 plants ; if acid phosphate of lime is employed, French 

 rye-grass will spring up in thickly serried blades. 



In all perennial plants, the underground organs are 

 usually very much greater in mass and extent than 

 those of annual plants. Whilst the roots of the latter 

 die every year, the former preserve theirs in a state of 

 readiness to absorb food at every favourable oppor- 

 tunity. 



The circle from which a perennial plant draws its 

 food enlarges from year to year ; if one part of its roots 

 finds little nourishment in a given spot, other parts 

 draw their supply from other spots richer in the food 

 required. 



Only a very small portion of the plants of a thickly 

 covered meadow will produce stems : the far greater 

 part will develoj)e only tufts of leaves ; and many will 

 for years be confined to the production of underground 

 suckers. 



For perennial grass and meadow plants, the produc- 

 tion of underground suckers is of the highest impor- 

 tance, since by them the plant is furnished with nutri- 

 ment at a time when a scarcity of supply would 

 endanger the life of annual plants. 



A good soil, and all other conditions of vegetable 

 life, will of course exert the same favourable influence 



