CO 



GOLDEN WARBLI.nS. 



The entire leg is longer in the Yellow and the feet are larger. The femur 

 is of the same length in both ( .60 ), but the tibia of the Yellow is .09 longer, 

 and the tarsus .07. 



Internally we find some striking differences between the two. The gullet 

 (if the Yellow is .05 longer to the proventriculus, but the proventriculus itself is 

 .0.5 shorter ( see Fig. 36, I p, Yellow : Dp, Chestnut-sided ), but the stomach 

 of the Yellow is larger: .50 long, .40 wide and .21 thick ( see Fig. 36, I s ), 

 while that of the Chestnut- sided is of a different form, being proportionately 

 thick for its size : .40 long, .37 wide and .21 thick ( see Fig. 36, D s ). The 

 walls in that of the Yellow are somewhat thick3r proportionately ( see Fig. 36, 

 H w w ) than in that of the Chestnut-sided (see Fig. 36, C w w ). The fold 

 of the duodenum is about the same length in both in proportion to the size of the 



Fig. 35. 



A, body of TeHow Warbler; B, same of Chestnut-sided : M. neck; K. keel; A, abdolneli ; landlli 



oil sacks, detached. 



stomach, as is also the pancreas ( see Fig. 36, 1 1 ), The intestines of the Yel- 

 low measure 3.25 to the coecal appendages, and are .60 longer than those of the 

 Chestnut-sided. The liver is larger in the Yellow, but the large stomach causes 

 a iijreater difference in size between the right lobe and the left ( see Fig. 34, A, 

 Yellow ; B, Chestnut-sided i.R, being the liver and s, the stomach in both ). 

 The tongues of both are bifid, but that of the Yellow is rather more fleshy and 

 not as well provided with fine bristles at the tip ( see Fig. 36, A, tongue of Yel- 

 low : B, that of Chestnui-sided. 



SUMMARY. 



I will now give a summary of the chief points of difference between these two 

 birds, and, as far as possible, a reason for these differences. I may say in ad- 

 vance that I know, from a careful study of the American Warblers, begun many 

 years ago, and continued at various times as opportunities offered, that each of 

 these birds is a typical representative of the genus to which it belongs. 



