EXPLANATION OF PLATES. 



Plate IV. Digestive Organs of the Peregrine Falcon, Falco 



peregrinus. 



Fig. 1. Head. 



a, upper mandible. 



b, cere, and nostril. 



c, dorsal outline of upper mandible. 



d, angle of mouth. 

 d, e, lower mandible. 



d, b, base of upper mandible. 



d, f, base of lower mandible. 



y, angle of lower mandible. 



g, dorsal outline of lower mandible. 



Fig. 2. Roof of Mouth. 



a, b, c, posterior aperture of tlie nasal 

 organs. 



a, a, its anterior part, or palatal slit. 



b, €, series of pointed papillte. 



c, a, a, flat surface, on which the tongue 



is applied. 



d, curved series of papillae. 



f, edges of upper mandible. 



Fig. 3. Tongue and aperture of Wind- 

 2)ipe. 



a, b, tongue, soft, rounded. 



b, papillae at base of tongue. 



c, aperture of glottis. 



d, d, sides of pharynx. 



e, posterior part of pharynx. 

 f,f, pointed papillae. 



Fig. 4. Tongue, Trachea, Intestinal 

 Canal, Heart, and Liver. 



a, b, b, tongue and hyoid bones. 



c, d, trachea, 



d, e, bronchi. 



e,f, divisions of aorta. 



g, h, heart. 



h, pericardium left on one side. 

 i, j, lobes of the liver. 

 a, b, d, oesophagus. 



k, Jc, dilatation of oesophagus, or crop. 



/, commencement of intra- thoracic por- 

 tion of oesophagus, passing be- 

 hind the heart and liver, but 

 shewn by Fig. 5. 



n, 0, stomach. 



0, one of its tendons. 



p, q, r, duodenal fold of intestine. 



X, anus or vent. 



Fig. 5. Part of (Esophagus, Stomach, 

 and Intestine. 



I, m, lower part of oesophagus. 



m, proventriculus. 



n, muscular fibres of stomach, 



0, one of its tendons. 



p, q, r, duodenal fold of intestine. 



p, pylorus. 



r, entrance of biliary ducts. 



s, s, pancreas. 



t, gall-bladder. 



u, V, w, intestine. 



w, cloaca. 



X, anus. 



Fig. 6. Rectum and Cceca. 



a, b, rectum. 



a, a, cceca. 



c, d, ureters, entering at e, below which 



is the aperture of the bursa of 



Fabricius. 



Fig. 7. Proventriculus laid open. 



a, b, longitudinal section of proventri- 

 culus. 



1, 2, 3, 4, proventricular or gastric 

 glandules slightly divided into 

 four masses ; their orifices seen 

 on the inner surface. 



