NATURE OF PLANTS 45 



;vour the cacti after the spines are burned off. The develop- 

 ent of these storage cells accounts for the fleshy character of 

 any alkaline, saline, and desert plants, many of which depend 

 3on organic compounds lodged in their cells for the retention of 

 Iter rather than upon the development of cutin. Curiously 

 lough there are many examples of xej^Elwiiic plants living in 

 )gs and marshes, as, for example, the rushes and sedges, the 

 )rse tail ferns (E quisej um) , the lamb kill (Kalmia) and leather 

 af (Chamaedaphne) , etc. The cause of the association of these 

 ants with aquatic forms is not known. In exposed moors and 

 5aths these reduced forms would have decided advantage 

 icause of their protection against drying winds. Our sedges and 

 ishes are exposed to very intense heat and light which may 

 Dssibly cause so heavy a tr anspirati on that these plants are not 

 jle to meet the loss by root absorption. This is the more 

 robable because in many instances the absorption of water by 

 ants living under such conditions is slow owing to lack of 

 cygen and to the concentration of the water in which the roots 

 ■ow. 



