INFLUENCE OF HEREDITY 101 



At first thought it might require a stretch of 

 the imagination to understand how this could be 

 yet a closer inquiry shows that the process was 

 as gradual and as surely progressive as the trans- 

 formation of the cactus. 



In clover, as with all other plants, there has 

 always been variation some few individuals 

 have always had the white and black markings. 



At some time in the history of the plant those 

 without the markings may have been destroyed, 

 and so, responding to this new environment, the 

 markings became more and more pronounced 

 until now we have not only white triangular 

 markings, but deep black splotches and red and 

 yellow colors intermixed in curious figures. 



From these markings we can readily imagine 

 the history of this Chilean clover most of the 

 family having plain leaves inherited from an 

 ancestry which found no need to protect itself 

 from an enemy with an occasional outcropping 

 of poisonous-looking color splotches the inher- 

 itance of environments in which self-protection 

 was necessary. 



Or we might consider the ice plant (Mesem- 

 bryanthemum crystallinum) which protects it- 

 self from the heat and evaporation of the sun by 

 surrounding itself with tiny water droplets which 

 have the appearance of ice; or the wild lettuce, 



