BIOMETRY AS A METHOD IN TAXONOMY 1 



PROFESSOR CHARLES LINCOLN EDWARDS 

 Trinity College 



We take it for granted that the systematic description 

 of plants, and animals, is not the province of the amateur, 

 however interested he may be in a special group of living 

 tilings. To the contrary this work should be done by 

 the professional botanist, or zoologist, and demands a 

 high grade of trained skill and judgment. More intel- 

 ligence is needed than suffices to carefully fill out a card 

 for a catalog, and yet how often do we find descriptions 

 of species that would be discreditable to even a librarian's 

 assistant ! 



The characters of one species are sometimes described 

 as "smaller," "longer," "darker" or "lighter" than 

 those of another, but upon reading the description of the 

 other species referred to, the characters are again equally 

 lacking in exactness. It is useless to enlarge upon this 

 item, for every naturalist is sadly familiar with such 

 imperfect and inadequate descriptions. 



Biometry offers a method of great value for the study 

 of specific characters, and the consequent clear and 

 definite statement of the results of such study. There 

 are workers either frightened at the mathematics of the 

 method, or scornful of the whole thing on the general 

 principles of conservatism, or prejudice. The mathe- 

 matics of biometry, considered merely as a biological 

 working method, is that of simple arithmetic, with no 

 operation more complicated than the extraction of the 

 square root. 



It is certainly of great advantage to record in the 

 standard deviation an exact mathematical statement of the 

 variability of a character in place of the sometimes ut- 



1 Read at the Seventh International Zi...|i.^i.- :I | < 'onurfss. Boston, August, 

 1907. 



