48 GENETICS 



flowering plants, the seeds of which in turn produce 

 double flowers. 



The giant primrose is a mutation from a normal 

 strain of known pedigree. (Keeble.) 



"Mutations in certain pericarp color patterns of 

 maize are so common that a wide range of variability 

 results. Selection is able from such material to iso- 

 late types relatively stable but very diverse in appear- 

 ance." (Emerson and Hayes.) 



That plant mutations may occur in nature and per- 

 sist successfully without isolation or external selection 

 is shown, for instance, by Schaffner 1 who reports an 

 unusual white verbena growing wild in Ohio over about 

 a square mile of territory along with the typical pur- 

 plish blue Verbena stricta without transitional forms. 



Hayes discovered a tobacco mutant in which the 

 average number of leaves produced was 70 instead of 

 20, and Cockerell found a single red mutant plant of 

 the sunflower, Helianthus lenticuLaris coronatus, which 

 has bred true. The list of similar plant mutations 

 could be almost indefinitely extended. 



5. SOME MUTATIONS AMONG ANIMALS 



In 1791 a Massachusetts farmer, by name Seth 

 Wright, found in his flock of sheep a male lamb with 

 long, sagging back and short, bent legs resembling 

 somewhat a German dachshund. With unusual fore- 

 sight he carefully brought up this strange lamb be- 

 cause it was an animal that could not jump fences. 



'Ohio Naturalist. Dec., 1906. 



