FLAX AND TOBACCO 



165 



A list of these characters and of the authority for the inheritance 

 is here given. Not all papers on this subject are included. Those 

 given show the general behavior of many of the characters in 

 inheritance. 



TABLE XXXVIII. INHERITANCE OF TOBACCO CHARACTERS AS SHOWN BY 

 RESULTS 01 CROSSES 



Character 



Grown in 



Authority 



Spread, length and diameter 

 of corolla. 



Sucker inheritance . . 

 Base of leaf. . 



F, to F 3 Goodspeed, 1912, 1913. East, 



19166. 

 i to F 3 \ Johnson, 1919. 

 to F 3 : Howard, 1913 



The results obtained in these studies of tobacco show that 

 segregation occurs in F z for size characters and that forms 

 similar to the parents as well as new sorts may be obtained in 

 later generations. 



Environment as a Factor in Tobacco Breeding. It is a matter 

 of common knowledge that environmental conditions widely 

 modify the expression of characters. This is particularly notice- 

 able in tobacco, where quality, size, and shape of leaf are of such 

 marked importance. A belief has been frequently expressed 

 that environment causes a breaking of type. The following 

 quotation from Sham el (1910) emphasized this view for tobacco: 



"The writer believes that the two efficient means of inducing varia- 

 bility as a source of new types are change of environment and crossing. 

 So far as the writer is concerned, the change of environment usually 

 the growing of southern grown seed in the north is the most effective 

 means of inducing variability." 



Statements of this nature have been used as evidence that 

 environment modifies the characters of a pure line by inducing 



