PLATE XX 



Spanish Bayonet, Yucca (Hesperoyucca) 

 whipplei, a Conspicuous Member of the 

 Chaparral Belt of Southern California. The 

 Panicle of Heavily Fragrant, White Flowers 

 Kises Eight or Ten Feet Above the Dense 

 Cluster of Stiff, Sword-like Leaves at the 

 Base. The Method of Fertilization by the 

 Pronuba Moth Which Lays Its Eggs in the 

 Flower Is a Striking Example of Interde- 

 pendence of Plant and Animal. 

 Photograph by Harley P. Chandler. 



