THE INTRODUCED SPARROW. 9 



ivory white of certain vireos. An attempt was made to arrange 

 the colors in sequence, but after many fruitless efforts the 

 plan of disinterested selection, above mentioned, was adopted. 

 The British and American eggs were thoroughly mixed 

 together and the request was made that twenty-five eggs 

 which presented the greatest variation toward the kingbird 

 type should be selected first; then twenty-five of the somber 

 type; third, twenty-five of extremely light color; and, fourth, 

 twenty-five anomalous varieties. Some hours were spent in 

 making the selection of one hundred eggs, and with the results 

 indicated on Diagram III, where b represents the British eggs 

 and A represents the American. 



KINGBIRD TYPE. SOMBER TYPE. LIGHT TYPE. ANOMALOUS. 



b b b b 



b b b A 



b b A A 



b b A A 



b b A A 



b b A A 



b b A A 



b A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



A A A A 



DIAGRAM III. This diagram is designed to illustrate the preponderance of extreme color 

 variation on the part of American eggs. A indicates American, b indicates British eggs. 



Of the kingbird type and of the somber type there were over 

 twice as many American as British eggs. There were among 

 the light eggs nearly twelve times as many departures from the 



