FORM AND IIAIUT: TIIK WIX(}. 



lY 



oTirans we sliall dirt'ct our aftt^'iitinii to tlieir external form 

 rather than tlu'ir internal structure. 



The irZ/yy. — Ijirds' wings are ])riinarily orc^ns of 

 loeoniotion, but tliey are also used as wea])ons, as musical 

 instruments, in expressing- emotion, and they are some- 



Fio. 4. 



-Young Iloatzin, sliowing use of Looked fingers in climbing. (After 

 Lucas.) 



times tlie seat of sexual adornment. As an or<xan of loco- 

 motion the wing's most pnmitve use is doubtless for 

 climbing, (lallinules, for instance, have a small spur on 

 the wrist or "bend of the wing," and the young birds 

 use it to assist their progress among the reeds. A more 

 striking instance of this nature is shown by that singular 

 South American bird, the Iloatzin {Ojmthocomus oris- 



