THE ANATOMY OF THE INDIAN ELEPHANT. 55 



The chief difficulty attending this explanation springs from 

 the small size of this pharyngeal pouch. In our example, which, 

 it must be remarked, was by no means of full stature, the pouch 

 could not be distended so as to hold a pint of water. This 

 objection is not fatal to the hypothesis advanced by Dr Watson.^ 

 Eegurgitation from the stomach may be effected slowly and 

 continuously until the requisite supply is yielded. It seems to 

 us that the pharyngeal pouch must be unimportant as a mere 

 reservoir of fluid, but as a water-tight circular valve it may be 

 essential to the process of withdrawal. Behind the velum 

 palati is a somewhat larger cavity, but the entrance to the wind- 

 pipe lies in its floor, and this is not therefore a very likely re- 

 ceptacle of fluid. If our examination of an immature elephant 

 yields data in the least trustworthy, it is hard to suppose that 

 even in the adult a gallon of water can be retained anywhere 

 between the stomach and the proboscis. 



We do not know enough of the habits of the living animal to 

 say whether or not the food is moulded and lubricated into a 

 bolus, but the form, structure, and glandular surface of the 

 pharyngeal pouch would be well adapted to such a practice.^ 



' Dr Watson informs us that lie considers the pharyngeal pouch unimportant as 

 a mere reservoir, " though the presence of certain muscles not found in other 

 animals would appear to indicate that the elephant possesses a certain power of 

 increasing or diminishing the size of the pouch, and the necessity for this is hy 

 no means evident upon the supposition that the sphincter arrangement is the only 

 faison d' etre of this pouch." 



2 Professor Owen describes the back of the mouth of the Camel in these words: 

 — "A broad pendulous flap hangs down from the fore part of the soft palate, and 

 usually rests upon the dorsum of the tongue. The velum palati extends beyond 

 this process some way down the pharynx, and terminates by a concave border. 

 The pharynx behind the velum dilates into a sac. In the rutting male the 

 palatal flap is greatly enlarged. I have found it extending 10 inches down the 

 pharynx, passing below the margin of the soft palate and the opening of the 

 larynx, into the oesophagus : in the living animal it is, at this season, occasionally 

 protruded, with a belching noise, from the mouth. Its surface shows the pores 

 of innumerable mucous crypts, and in the ordinary state, in both sexes, the flap 

 may apply its own secretion, and water regurgitated from the storage cells of the 

 stomach to the extended surface of the pharynx and root of the tongue so as to 

 allay the feeling of thirst and help the animal to endure the long remissions of 

 drinking to which it is liable in traversing the desert " (Comp. Anatomy of Ver- 

 tebrates, vol. iii. p. 395). In transcribing these remarks, we desire to offer no 

 opinion as to the validity of the explanation offered. The pharyngeal sac 

 described in the camel may throw light on the similar structure in the ele- 

 phant. 



