PASSERINE BIRDS OF NEW YORK 95 



is soon completed. The central rows of feathers tend to pre- 

 cede the outer and the moult advancing rapidly forward and 

 backward soon reaches the base of the head and the wide saddle 

 behind the shoulders, at both of which points will be found' the 

 last traces of new feathering. It is sometimes the first tract to 

 show new growth. If a species has a prenuptial moult this tract 

 is not usually involved unless all the body plumage is renewed, 

 except in a few cases where only the interscapular portion is 

 included with the head and throat. 



5. Ventral or Inferior Tract {Pteryla gastnei). From this 

 extensive tract grows the whole plumage of the lower surface 

 of the body. It may be said to begin at the interramal space, 

 it gives off two short auricular branches near the angle of the 

 jaw and it forks at the mid-neck into two lateral, or sternal, 

 branches which passing along the sides of the body, end on 

 either side of the vent or at some distance from it. On the 

 breast there is regularly a widening of the lateral bands, the ex- 

 ternal half of each ending abruptly under the wings nearly mid- 

 way between head and tail. 



It is not surprising that the first as well as the last traces of 

 a moult are frequently to be found on this extensive tract. A 

 few new feather follicles may be expected on either side of the 

 breast even before the proximal primary is lost and soon a 

 V-shaped band is seen, the point of the V reaching the mid- 

 throat forking. The tide of moult seems to sweep chiefly 

 backwards, beginning in the middle rows and new outbreaks 

 take place a little later on the throat. The sides of the chin 

 and throat may precede or follow as the case may be, the 

 throat in their feather development owing to the submalar 

 bands which seem properly to belong to the head tract. The 

 feather growth extending forwards from the breast is met by 

 that extending backward from the throat, the lower part of which 

 is consequently late in acquiring new feathers. The last 

 traces of moult in the ventral tract will be found at its ex- 

 tremities on chin and abdomen, or among the outer rows of 

 feathers where it is widest as at its forking and under the wings. 

 The feathers which hide the middle of the abdomen are con- 



