206 . ‘GENERAL ORNITHOLOGY. 
Fic. 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 uro-hyal; c, c, horns of hyoid bone; d, a, 
genio-hyoid muscles; e, e, stylo-hyoid muscles; J, f, cleido-hyoid muscles; g, h, é, esophagus; j, proventriculus; 
or secretory stomach; k, gizzard, or gigerium, the muscular stomach; J, m, n,m, intestine, duodenum to rectum ; 
