THE ROOT. 237 



pare it now with B (Fig. 406). Observe the absence 

 of hairs at the tip. 



The first formation of roots in plants is quite in- 

 dependent of the medium in which they exist. But, 

 when the roots begin to act, their growth depends 

 very much upon the medium that surrounds them. 

 If there is food, they grow ; and, the more abundant 

 the food, the more they multiply. Those rootlets 

 that come in contact with food, flourish and branch 

 in all directions; while those that find none, cease 

 to grow, or perish. Roots that grow in rich soil are 

 short and very branching ; while in poor soil they are 

 long, slender, and have few rootlets. 



Most plants with roots adapted to the soil will die 

 if they be left in air or in water ; while water-plants 

 die if their roots are placed in the earth. Yet there 

 are some plants which flourish equally well, whether 

 their roots are in the soil, in swamps and marshes, or 

 in water. For instance, rice will grow in pine-bar- 

 rens, in the tide swamps of the coast, or when its 

 roots are under water throughout its life. 



If, however, the seeds of many ordinary plants, 

 when sprouted, have their roots placed in water, care 

 being taken to keep the seed and stem in air, and 

 nourishment be supplied to them, they will produce 

 foliage, flowers, and seeds, the same as if grown in 

 the soil ; but, when thus started in water, they will 

 not bear transplanting into soil of the usual dryness. 

 If so transplanted, they may be kept alive by profuse 

 watering until the formation of new roots adapted to 

 the soil. Equal difficulty is met when plants, started 

 in the soil, have their roots placed in water. 



