COLLATERAL READINGS SUGGESTED: 



Darwin's Origin of Species, and Sexual Selection ; Wallace's Dar- 

 winism ; Grant Allen's On the Colors of Flowers, and The Color Sense : 

 Its Origin and Development ; Lubbock's Flowers, Fruits, and Leaves ; 

 Peckham's Sexual Selection in Spiders; Eimer's Organic Evolution 

 as a Result of the Inheritance of Acquired Characters ; Hinton's Life 

 in Nature. 



