APPENDIX I 



Incompatibility, the failure of self- or cross-fertilization by reason of 

 genetic similarity, within an otherwise freely interbreeding group; 

 especially limited to the effects of hindrances which act between 

 mating or pollination and fertilization. Stout 191 8. 



Classifiable into [Mather 1943): — 



Heteromorphic Incompatibility, which is associated with, and depen- 

 dent on, morphological variation including Heterostyly. 



HoMOMORPHic Incompatibility, which is not dependent for its action 

 on morphological variation (includes the types found in Nicotiana 

 and CapscUa and Heterothally — sometimes erroneously referred to 

 as sexuality — in fungi). 



Independence, the relation between two variates, the variation of each 

 of which is uninfluenced by that of the other. The opposite of 

 dependence and Correlation. 



Independent Comparisons, comparisons between observations whose 

 values are uninfluenced by changes in each other. Such comparisons 

 are termed Orthogonal and the functions from which they are 

 calculated are Orthogonal Functions (such as are used in manipu- 

 lating genetical data for the detection of hnkage). 



Individual, a unit of life considered either physiologically or genetically. 

 A genetic individual comprises all the derivatives of one fertihzation 

 up to the succeeding meiosis, or all the derivatives of one of the 

 four spores produced by meiosis up to the succeeding fertilization, 

 f . Clone. 



Inert Gene, a gene (defmition 3) which, through apparent lack of 

 mutation or effect in disturbing balance, has been assumed to be 

 inactive. Often associated with Heterochromatin. 



Information, Amount of, the quantity which characterizes a body of 

 data with respect to a parameter independently of the method of 

 estimating that parameter. GeneraUzed as the reciprocal of the 

 Variance of an efficient Statistic. 



Inheritance, Heredity. 



Blending Inheritance, the suppression of heritable differences by the 

 fusion of heredity in the hybrid offspring of a cross. (The Darwinian 

 assumption as opposed to particulate or Mcndelian Inlieritance.) 

 Sometimes wrongly used for Quantitative Inlieritance. 



Criss-Cross Inheritance, the resemblance of offspring to the parent 

 of opposite sex, owing to sex linkage on the X chromosome 

 V. Linkage. Bridges 191 3. 



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