VARIATION AND CORRELATION IN TIMOTHY* 



(Phleum pratense L.) 



Variation is the rule rather than the exception in all organisms; 

 therefore a study of living things is not complete without a knowledge 

 of their diversities. With the application of mathematics to the field 

 of biology, studies along this line have assumed greater importance, 

 for by the use of statistical methods we are able to determine with 

 exactness the range of variation in the species, the fluctuations from 

 time to time as the result of environmental influences, and the progress 

 the species is making in evolution. 



The object of the present study is to determine (i) the variations 

 which occur in the species Phleum pratense L. when grown under the 

 conditions which obtained during the experiment; (2) the relation to 

 each other of certain characters of economic importance which readily 

 lend themselves to measurement; (3) the variation from season to 

 season; (4) the bearing of these seasonal changes on the problem of 

 selection. 



MATERIAL AND METHODS 



The data upon which the present discussion is based were furnished 

 by the timothy experiment started at Cornell University in 1903 by 

 Professors T. F. Hunt and J. W. Gilmore. Samples of seed were secured 

 from 231 different sources throughout the world, 21 states, Canada, 

 Japan and 9 European countries being represented. In this discussion, 

 however, only the data from plants grown from American seed are 

 used. The sources of this seed and the number of samples received 

 from each state were as follows: 



New York 92 Iowa 



Wisconsin 16 Kansas 



Ohio 14 Maryland '..... 



Pennsylvania 14 Massachusetts 



Michigan 6 Missouri 



Maine 3 New Brunswick 



Connecticut 2 New Hampshire 



Delaware i South Dakota 



District of Columbia i Vermont 



Illinois I Virginia 



Indiana i West Virginia 



Unknown source (thought to be New York) 



Total, 163. 



♦Contribution No. VII, Laboratory of Experimental Plant-Breeding, Cornell University. 



421 



