No. 572] PATTERN DEVELOPMENT 479 



bred for pattern. The first steps in reduction are shown 

 in Fig. 49. Here there is seen first a crescentic band of 

 white feathers passing from eye to eye around the occi- 

 put. This is a primary break marking off the crown 

 patch posteriorly. This patch in birds, in contrast to its 

 development in mammals, is the main patch of the head, 



covering the area from the base of the bill to the eyes 

 and occiput. In Fig. 50 its posterior limit is similarly 

 defined by a primary break separating it from the neck 

 patches, and although it does not extend forward quite 

 to the eye in this specimen, it shows a beginning of sepa- 

 ration from the more lateral ear patches by virtue of the 

 indentations on each side posteriorly. In Fig. 52, the 

 crown patch is shown slightly reduced in extent and 

 wholly separate from the ear patches, which have become 

 inactive altogether. In Fig. 53 it has dropped out with 

 the latter. It is evident then that by greater or lesser 



