July 15, 1914 
Mutation in Egyptian Cotton 
301 
different times and in different places. An example of this phenomenon 
in Egyptian cotton is afforded by'the Nubari and the Yuma varieties. 
If the tendency to produce mutants is a result of remote or complex 
hybridization, the mutability of Egyptian cotton might be accounted 
for upon either of the following grounds: (1) The supposed hybrid origin 
of the type as a whole, or (2) later crossing with other types of cotton. 
Ever since mutation became recognized as a factor in the breeding of 
Egyptian cotton the following methods have been followed in Arizona: 
(1) Recognition and isolation of desirable mutants; (2) selection and 
comparison on the progeny-row basis of those individuals among their 
progeny which express most fully the desirable characters of the new 
type; (3) elimination from the seed-increase fields, preferably before 
blossoming begins, of the aberrant and otherwise undesirable individuals. 
Balls, W. L. 
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