INTRODUCTION. 



27 



in the fourth Jive. All the species described in this volume 

 have four toes. Generally one toe only, the first, is directed 



backwards, Fig. 6 ; but sometimes also the fourth or outer 

 toe, as is the case in Owls, Woodpeckers, Fig. 9, the Cuckoo, 



Fig. 10. 



Fig. 11. 



and the Wryneck. The toes are generally co- 

 vered above with large scales, named scutella, 

 but in some species there are scutella only at , 

 the end, the other parts being covered with 

 scales. The claws vary in length and form, 

 but the terms used in describing them are easily 

 understood. Thus they are nearly straight in 

 the Lark, Fig. 6 ; arched in the Nuthatch, 

 Fig. 10. 



The Plumage varies in texture, being dense, 

 compact, firm, glossy, loose, or downy. Each 

 feather, Fig. 11, is composed of the tube, a; 

 the shaft, b ; the outer web, c, and the inner 



