320 



in the same order, at the top. At the place of intersection of the line 

 of figures for one crop with the column of figures for another, will 

 be found the coefficient of the preference of the mourning-dove for 

 one of these crops as compared with the other, — the standard crop 

 being the one whose name is at the head of the column. Selecting, 

 as an illustration, the column headed "corn," and following it to its 

 intersection with the line for "meadows," we find there the coefficient 

 1.16, — the meaning of which is that for every hundred mourning- 

 doves found in a given area of corn fields, 116 would be found, ac- 

 cording to our data, in a like extent of meadows. If any number 

 of these birds found in corn fields is multiplied by the coefficient 

 1. 16, the product is the number which we may expect to find in 

 meadows of the same aggregate area. 



Reading upward from 1 in any column, one gets a descending 

 series of expressions for the densities of the dove population in crops 

 less attractive than the one named at the head of the column ; and 

 reading downward from the same point, a reverse series for crops 

 more attractive to doves than this standard crop. The figures on one 

 side of the diagonal line of l's are the reciprocals of those on the other 

 side. 



Tables of this description will be useful for a comparison of the 

 distribution and ecology of the several species at different seasons and 

 in different situations, and for a comparative study of the statistics 

 of bird distribution in different parts of the state and in different 

 states. 



