Ihilltlin No. 24. 1 1 



had not always existed as we see them now. We realize now that 

 Thrushes and Grebes belong to one great family and that their great 

 differences are due to their early differentiations, whereas the various 

 species of Warblers, for example, are only twigs of one branch of the 

 l)ird limb. Recent work in classification has been guided more or less 

 by this light, and yet it must be admitted that comparatively little 

 attention has been given to a bird's family and ancestrial relationships. 

 In other words, phylogenetic study of birds, as of other animals, is still 

 a little explored field ; and few subjects offer more opportunity than this 

 for the thoughtful and resourceful student. 



Some work along this line that I am doing in Harvard University has 

 suggested to my mind the organization of a committee of members of the 

 Chapter, who have opportunity and inclination for such work, to take up 

 a careful study of the various races of North American Song Sparrows, 

 from a phylogenetic standpoint. It is very desirable that we have the 

 co-operation of as many ornithologists as possible and that the various 

 life areas be represented as far as possible. First of all, as many skins 

 as are accessible should be gathered together, and the following meas- 

 urements made with great care with a pair of dividers. 



Bill. — Length from nostril to tip. Depth at base where feathers begin. 



Left wing. — Length of greatest chord. 



Tail. — Length from knob or papilla or "bishop's row" to tip of tail. 



It is desirable that all measurements be according to the metric system 

 and that those of the bill should be accurate to tenths of millimeters. 



Careful measurement of eggs are also desirable. After the work of 

 measuring has been completed, a study of the color patches may be 

 begun, and the following general principles should be borne in mind : * 



I. — That young birds and females, in so far as they differ from adult 

 males, are more primitive in coloring. 



II. — That the color spread over the greater portion of male birds is 

 the more generalized and the detailed markings the more specialized. 



III. — Variations are found to occur more frequently in extremities. 



Count the number of primaries and tail feathers ; observing also any 

 progression or correspondence in markings. If any variations are found, 

 they should be noted. Notice whether females or young males of one 

 race differ as much from those of another as the adult males. 



"^-'E volution of tlie Colors i of North American Land Birds | by \ Charles A. 

 Keeler. j San Francisco: \ California Academy of Sciences. ] January, 1893. { 361 pp. 

 ly plates. Very rich in suggestions. 



