l6o DwiGHT, Variations of ike American GoJdfnch. LApr. 



sity of the yellow of successive nuptial plumages of males, although 

 the depth of color varies somewhat according to the individual. 

 There are lighter and darker first nuptial plumages and similar 

 second or later nuptial plumages, but the variation in shade of 

 color between deep canaiy and pale lemon-yellow is surprisingly 

 small. The lesser wing-coverts serve to distinguish young breed- 

 ing birds from adults. 



The second prenuptial moult of salicamans probably averages 

 more extensive than the first. A grayish collar on the nape is 

 usually the last relic of the winter dress, but the yellow may be 

 considerably obscured by old feathers elsewhere. The end of 

 March usually finds salicama)is in nuptial dress, although there is 

 evidently great individual variation in its time of completion. If 

 the growth of plumage continues into the breeding season as 

 observed by Mr. Grinnell, it is a condition that is not found in 

 tristis although not without a parallel in other species of birds. 

 April is not represented in the series examined, but the birds of 

 late May seem to have completed their moult a good while before. 



The type of paUidus (Amer. Museum No. 52666, $ ^ May 3) is 

 a bird of the second summer or older. It is large, with a long 

 tail, and shows much white edging, but I do not consider it of a 

 paler yellow than tristis, and it would be hard to pick it out of a 

 series of tristis. 



The measurements in Table I show variations in dimensions 

 due to sex, to age, and to season, tristis being contrasted with 

 salicamans. As all the measurements are mine they are strictly 

 comparable. The wing is measured with dividers from the proxi- 

 mal end of the carpo-metacarpus to the tip of the longest primary, 

 /. ^., the eighth enumerating from the wrist outward; the tail from 

 the point of insertion of the middle pair of rectrices into the skin 

 to the tip of the longest, /. ^., the outer pair ; the tarsus and 

 middle toe along their greatest anterior length ; and the bill along 

 the chord of the culmen and also its greatest depth. 



