151 



him iutlate the ^jouch, uttering at the saM& tiw& 

 % Mlt>w tokfng ndl^fe,* for %M pnadiictfqii of 

 which the rushing of the ait iz^to the Sac was 

 evidently an adjunct. The inflation of the pouch 

 was not, however, confined to anger ; for w iicn 

 pleased he would purse the mouth, drive the air 

 with an audible noise into tfie sac j when yawn- 

 mg» at was alW iniiated ; and in iill imtBmse$^ 

 (I'xeopt wlicn excited by auger,) lie would gfa- 

 duallv empty the sac, as if he derived a pleasure 

 from it. When the sac has been distended, 1 

 hme often pressed on it, and forced the air con- 

 i^imi mMa. it the shoath, th^ aMsial not 

 &»iimti^ at the time any sign of its being an 

 annoyance to him. When nttering; the l)arkino: 

 noise, the ponch is not inflated to the same ex- 

 tent as when lie yawns. It has been stated in 

 an Amei^tmzi publl^^i;^, thil l^e me of air 

 sac is for a swimming bladder. It may be said 

 in refutation, (if tlie assertion isuot Loo absurd to 

 refute,) that Uugka uever evinced any pai-tiality 

 for swiuiniing, although provided with such an 

 ap]>aratu:8f; trttt' Oiie day, thinking that a washing 



* When tlie barking noise was made, tlie lips were pursed 

 «iut^ M fhe ittr driven j^ta issa^ fOi iim ^am^ time timt 

 the sound w^s utteml, the lower jaw Wfts «Isi» ^ IHtle 

 protruded. 



