The inheritance of certain Quantitative 
Characters in Tobacco. 
By H. K. Hayes. 
The Connecticut Agricultural Experiment Station. 
(Eingegangen: 25. Januar 1913.) 
The discovery of Nırsson-EHLE (:09) that certain hybrids are 
heterozygous for two or more separately inherited factors, either of 
which is alone capable of producing the same character, laid the 
foundation for the proof of the generality of the Mendelian inter- 
pretation of inheritance in sexual reproduction. NILSSON-EHLE showed 
that in such cases, with complete dominance, the F, ratios became 
15:1, 63:1 and so on instead of the simple 3:1 usually obtained. 
It was from similar facts obtained independently that East (: 10) 
made the first Mendelian interpretation of the inheritance of quanti- 
tative characters by assuming absence of dominance, but the few 
data he presented in its support would not have been convincing 
if it had not been for the work of the Swedish investigator. 
Soon a number of biologists made use of this new development 
of Mendelism, and the following investigations in quantitative charac- 
ters may be so interpreted: East (:11) and East and Hayes (:11) 
working with height of plants, length of ears, weight of seeds, and 
row Classes of maize, SHULL (:10) row classes of maize, EMERSON (:10) 
for shapes and sizes in maize, beans and gourds, TAMMEs (:11) for 
certain characters of Zinum forms, TSCHERMAK (:II) (:12) for time of 
flowering in peas and for weight of seeds, HavEs (:12) for height of 
plants, area of leaves, and number of leaves in tobacco, PHILLIPS 
(:12) for body size in ducks, Davis (:12) for Oenothera characters, 
WEBBER (:12) for plant characters of peppers, GILBERT (:12) for 
plant characters in tomatoes, BELLING (:12) for certain characters 
of beans, McLENDON (:12) for cotton characters. 
The difficulty of determining the inheritance of such complex 
characters correctly is greatly increased, owing to the fact that 
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