206 
GENERAL OMNITHOLOGY. 
Fig. 101. — Respiratory and vocal organs of the Rook, Corvus frugilegus, an Oscine Passerine bird; nat. size, 
after Macgillivray. 1. a, tongue; b, basi-branchial, commonly called iiro-hyal; c, c, horns of hyoid bone; d,d, 
genio-hyoid muscles; e, e, styio-hyoid muscles; /,/, cleido-hyoid muscles; g, h, i, oesophagus; j, proventriculus ; 
or secretory stomach ; k, gizzard, or gigerium, the muscular stomach ; I, m, n, n, intestine, duodenum to rectum ; 
