53 



water plants as eel-grass, contain them. 



Reason for many root-hairs, the increase of ahsor"bent surface. 



Iteaning of reduction — Two theories. 



1. Food obtaining so easy that organs disappear. 



2. Conditions so hard that the plant is unable to develop all its 

 organs . 



The food is so scattered through the water that it is difficult 

 especially in stagnant water, for the plant to obtain what it needs. 



v/liy are so many water plants so similar ? Because of similarity 

 of environment. Water plants show gradual decrease of root organs 

 and use of leaves as absorbent organs, hence leaves take on a root- 

 like, finely divided form. 



c. Saprophytism . 



Plants which ob.tain their food from decaying organic matter. 

 Many fungi are saprophytes, but fevif among- the higher plants. All 

 plants seem to enjoy some decaying organic matter, hence most plants 

 are saprophytes in part where they have an opportunity. Autophyte — 

 a plant absolutely Independent. 



d. Parasitism . 



Plants which live on living parts of other plants. Intimate r 

 relations of parasite and host. Rafflesia— no leaves, no stem, but 

 a root system, like fungal threads and immense flowers. Pound in W. 

 I. Some plants are both saprophyte and parasite. Associated with 

 this feature, we have carnivorous plants. 



e. Mutual ism- r where two organisms are of benefit, each to the other. 



Ex. tubercles of Leguminosae. Ilycorhiza in Beech, Birch, Alder, 



and many of Heath family. These are nitrogen gatherers. 



