1898] GULAR POUCH OF THE (IRE AT BUSTARD 317 



1 legland ; but ... is a separate and distinct, though delicate 



bladder After describing the very extraordinary evolutions of 



this bird during periods of display, and the great inflation of the neck 

 with which they are accompanied, he goes to remark that " All these 

 facts would certainly seem to favour the idea that the pouch is 

 intended to contain air, and that by the action of the muscular tissue 

 covering it conjointly with that of the sphincter at the mouth, the 

 Bustard may thereby be assisted ... in producing the peculiar 

 sound (resembling ' ook '), which is only to be heard during the time 

 when the pouch is most developed. . . ." 



Fig. 1.— The display of the Great Bustard, Otis tarda (after Wolf). 

 From Newton's " Diet, of Birds." 



These two preparations afterwards came into the possession of 

 the Royal College of Surgeons, and were described by Sir William 

 Flower (6). The larger of the two sacs when empty measured 

 nine inches in length, and when moderately distended with water 

 was found to hold three imperial pints. 



" Both of the sacks," he writes, " had within them a few short 

 pieces of grass and leaves. There appears to be no glandular struc- 

 tures connected with the walls ; indeed, the whole character of the 

 sack points to its being a simple reservoir, probably for fluid, more 

 analogous to the submandibular pouch of the Pelican than to anything 

 else in the class Aves. But in the absence of fuller information as 

 to the economy and habits of the bird, I refrain from speculating 

 upon the purpose of this singular and apparently inconstant organ." 



With l)r Cullen's investigations and their confirmation by Pro- 

 fessor Flower the existence of a pouch at least in some individuals 

 was placed beyond cavil. 



