Fig. 12. The stems ot the giant cactus do not bear leaves. Some of the shrubs 

 in this desert scene have leaves only during rainy periods. Photo by U. S. Forest 

 Service. 



Fig. 13. A flower and buds of Raffiesia, a root-parasite in the East Indies. The 

 species pictured above occurs in the Philippines. A species in Sumatra closely 

 resembles it in form and habit and has flowers three feet in diameter. Photo from 

 Phihppine Bureau of Science. 



