FAMILY CHARACTERS. 



Second, the walls of the stomach are greatly thickened and 

 it is lined v/ith a hard, mucous membrane (see fig. 3, b). 



This enlargement of the gullet into a species of crop and 

 the thickening of the walls of the stomach is not, as is quite 

 u sual in birds so characterized, accompanied by a special elon- 

 gation of the cceca, for the natural food of Sparrows etc., 

 is usually the seeds of plants and trees which contain more 

 Fig. 1. Ylq. 2. 



Base cf [tiimaries, Witli Bill of Rose-broast- 



the webs removed, of ed Grosbeak. A, side 



right wing of a White view ; i, Section at base, 



throated Sparrow. A, 

 forearm, w. wrist p, pri- 

 maries, iL digits. T, spu- 

 rious primaries. 



nutritious matter than much food eaten by the Grouse and 

 allied groups, which do have the elongated coeca for retention 

 of material which contains a comparatively small amount of 

 nutritious matter, hence this must be retained in the intes- 

 tine for a considerable length of time in order that all which 

 is of benefit to the bird may be assimilated. 



The sternum, which with its accompanying bones, the cor- 

 acoids, scapula and furcula (see fig. 4 ) are all subject to con- 

 siderable change in varying genera. The coracoids are 

 never longer than the top of the keel but are sometimes equal 



