HERITABLE DIFFERENCES 47 



the biological literature of the last thirty-five years, 

 is after all the most fortunate organism for demon- 

 strating mutation since its "mutations" may represent 

 simply combinations becoming isolated from something 

 already present as the result of past hybridization. 

 In either case the new form would breed true and behave 

 like a true mutation. 



4. PLANT MUTATIONS FOUND IN NATURE 



The oldest known authenticated case of a plant 

 mutation is the oft cited instance of the "fringed 

 celandine," Chelidonium laciniatwm, which made its 

 appearance in the garden of the Heidelberg apothe- 

 cary Sprenger in 1590 among plants of the "greater 

 celandine," Chelidonium majus. The fringed celan- 

 dine bred true at once and is now a widespread and 

 well-known species. 



The purple beech has appeared historically as a 

 mutant among ordinary beeches upon at least three 

 occasions in widely separated localities, and it has 

 always given rise to a constant progeny. 



The "Shirley poppy," notable for its remarkable 

 range of color, which was discovered in 1882 by Rev. 

 W. Wilks, originated from a single plant of the small 

 red poppy, Papaver rlioeas, which is commonly found 

 in English cornfields. 



The first double petunia was found in 1855 in a 

 private garden in Lyons. (Ziegler.) Other instances 

 are known of double flowers among roses, azaleas, 

 stocks, carnations, primroses, etc., arising from single 



