54 STUDIES IN COMPARATIVE ANATOMY. 



backwards cannot be altered, as the thyroid cartilage is thereby pre- 

 vented from being approximated to the hyoid bone. . . . An elephant 

 can, as the quotations sufficiently prove, withdraw water from his 



Fig. 2.— E, E, pharyngeal pouch. F, superior constrictor. G, stylo-glossus. 

 H, hyo-glossus. K, small muscle, which diminishes the depth of the 

 pharyngeal pouch. L, genio-glossus muscle. (For the use of the wood- 

 cuts of figs. 1 and 2 we are indebted to Professor Turner. ) 



stomach in tAvo ways : firsb, it may be regurgitated directly into the 

 nasal passages ^ by the action of the diaphragm and abdominal muscles, 

 the soft palate being at the same time depressed, so as to prevent the 

 entrance of water into the mouth. Having in this manner filled the 

 large nasal passages communicating with the trunk, the water contained 

 in them is then forced through the trunk by means of a powerful 

 expiration ; or, in the second place, the water may be withdrawn from 

 the cavity of the mouth by means of the trunk inserted into it. Now, 

 in this case, it is manifestly impossible that the water can be contained 

 within the cavity of the mouth itself, as I have already shown that 

 the lips in the elephant are so formed as effectually to prevent this. 

 The water regurgitated is, however, by means of the elevation of the 

 soft palate, forced into the pharyngeal pouch. The superior aperture 

 of this pouch being much narroAver than the diameter of the pouch 

 itself, and being completely surrounded by the muscular fibres of the 

 stylo-glossus on each side, and the root of the tongue in front, which 

 is prolonged backwards so as to form a free sharp margin, we have 

 thus as it were a narrow aperture surrounded by a sphincter muscle, 

 into which the trunk being inserted and grasped above its dilated 

 extremity by the sphincter arrangement just referred to, air is thus 

 effectually excluded, and the nasal passages being then exhausted by 

 the act of inspiration, water is lodged within these passages to be used 

 as the animal thinks fit, either by throwing it over his body, or again 

 returning it into his mouth." 



^ For remarks on this passage see p. 80. 



