176 THE VOYAGE OF H.M.S. CHALLENGEE. 



The palate of Aptenodytes (PI. XV, fig. 4) is covered by elongated recurved 

 papillae, which are more slender than the corresponding structures in Pygosceles. They 

 are arranged in eight longitudinal rows, four on either side of the middle line. The 

 papillae of the central are larger than those composing the lateral rows. Behind the gape 

 the papillae are of much smaller size, but are still arranged in parallel rows, of which 

 six or seven may be counted on either side of the middle line. These together form an 

 elongated patch, which corresponds in position to that of the laryngeal pads on the floor 

 of the mouth. The papillae disappear entirely at the commencement of the oesophagus. 

 The palate is completed in front by an elongated oval plate, the anterior extremity 

 of which is prolonged forwards as a narrow spine, which to some extent fills up the 

 interval between the superior maxillary bones of opposite sides. This plate is perfectly 

 smooth and devoid of papillae. In this respect Aptenodytes difi"ers from Pygosceles, while 

 it agrees with both Eudyptes and Spheniscus. The palatal and parotid groups of salivary 

 follicles are well defined, but the lingual group can scarcely be said to exist. ^ The latter 

 consists of only a few isolated follicles, the openings of which are scattered irregularly 

 over the floor of the mouth, instead of forming a weU-defined patch on either side of the 

 laryngeal pads, as in Eudyptes. 



The ffisoPHAGUS. 



By the term oesophagus I understand that portion of the alimentary canal which 

 extends from the cavity of the mouth backwards to the anterior border of the glandular 

 portion of the stomach, the so-called proventriculus of some authors. The description of 

 the proventriculus will be incorporated along with that of the stomach. 



The oesophagus, thus defined, measures in Eudyptes chrysocome from Tristan 

 d'Acunha, 9 inches in length. As it passes backwards from the mouth it occupies the 

 middle line of the neck, having the trachea below it. At the posterior part of the 

 cervical region, however, in consequence of the great projection forwards of that portion 

 of the vertebral column, which, as previously noticed, actually comes in contact with the 

 furcular angle, the oesophagus is displaced to the right, and at this spot rests against the 

 right side of the spine, lying between the latter and the right limb of the furculum 

 (see PI. VIIL). Having reached the aperture of the thorax, the oesophagus regains 

 the middle line of the neck, where it is crossed superficially by the bifurcation of 

 the trachea. Beyond this point it deviates to the left, and comes into contact with 

 the posterior surface of the left lobe of the liver, opposite the upper border of which 

 it becomes continuous with the stomach. The transition from the oesophagus to the 

 stomach is so gradual, that it is impossible from an inspection of the exterior of the 

 organs to determine where the one ends and the other begins. On opening the tube, 



' According to Eeid, Proc. Zool. Soc, 1835, p. 147, Aptenodytes patachonica possesses only one pair of salivary glands — 

 the sulimaxillary. 



