THE LEAVES 77 



body of another living plant or animal, it is termed 

 a parasite, and a brief study has already been made 

 of some of the characteristics of species of this kind 

 (§ 50). If its food consists of the substance of the 

 decaying bodies of other organisms, it is then termed 

 a saprophyte. Bacteria and mushrooms and moulds 

 ofEer most of the examples of both classes. 



96. An association without chlorophyl. — It has 

 been pointed out in a previous paragraph that some 

 species of higher plants have fungi united w^ith their 

 roots, forming a partnership which is of mutual 

 benefit. This partnership results in the seed plant 

 securing food without making it in the usual manner, 

 so these species lose their green color because of 

 disuse. The leaves also decrease greatly in size, 

 lose some of their tissues, and their characteristic 

 position with regard to light. The Indian pipe, 

 coral root, pine sap, and others are striking illustra- 

 tions of this action. 



97. Pitchered leaves. — Quite a large number of 

 species have changed their leaves in such manner 

 that they serve as traps for catching and holding 

 animals. The bodies of these creatures are digested 

 and used as food. The greatest variety is exhibited 



