STATISTICAL METHODS 



WITH SPECIAL REFERENCE TO 



BIOLOGICAL VAKIATION. 



CHAPTER I. 



ON METHODS OF MEASURING ORGANISMS. . 

 Preliminary Definitions. 



An individual is a segregated mass of living matter, capable 

 of independent existence. Individuals are either simple or 

 compound, i.e., stocks or corms. In the case of a compound 

 individual the morphological unit may be called a person. 



A multiple organ is one that is repeated many times on the 

 same individual. Example, the leaves on a tree, the scales 

 on a fish. 



A character is any quality common to a number of indi- 

 viduals or to a number of multiple organs of one individual. 



A variate is a single magnitude-determination of a character. 



Integral variates are magnitude-determinations of charac- 

 ters which from their nature are expressed in integers. Such 

 magnitudes are expressed by counting; e.g., the number of 

 teeth in the porpoise. These are also called discontinuous. 



Graduated variates are magnitude-determinations of char- 

 acters which do not exist as integers and which may conse- 

 quently differ in different variates by any degree of magni- 

 tude however small; e.g., the stature of man. 



A variant, among integral variates, is a single number-con- 

 dition, e.g., 5 (flowers), 13 (ray-flowers), etc. 



A class, among graduated variates, includes variates of 

 the same or nearly the same magnitude. The class range 

 gives the limits between which the variates of any class fall. 



Individual variation deals with diversity in the characters 

 of individuals. 



Organ variation, or partial variation, deals with diversity in 

 multiple organs in single individuals. 



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