of the Genera Tetrao and Ortyx. 135 



Trachea unusually large, and very strong. Gizzard dispro- 

 portionately large, having but little muscular substance ; 

 and the horny consistence of the inner coat, so conspicuous 

 in most species of this genus, is in the present remarkably 

 thin, in many so thin, that it can only be observed but by 

 careful examination. The pebbles in it seldom exceed 30 or 

 40, generally white quartz. Two caecal appendages, mode- 

 rately long, beautifully grooved or longitudinally fluted. 



The flight of these birds is slow, unsteady, and affords but little 

 amusement to the sportsman. From the disproportionately small, 

 convex, thin-quilled wing, — so thin, that a vacant space half as 

 broad as a quill appears between each, — the flight may be said 

 to be a sort of fluttering more than any thing else : the bird 

 giving two or three claps of the wings in quick succession, at the 

 same time hurriedly rising ; then shooting or floating, swinging 

 from side to side, gradually falling, and thus producing a clapping 

 whirring sound. When started, the voice is Cuck, cuck, cucky 

 like the Common Pheasant. They pair in March and April, 

 Small eminences on the banks of streams are the places usually 

 selected for celebrating the weddings, the time generally about 

 sun-rise. The wings of the male bird are lowered, buzzing on 

 the ground, the tail spread like a fan, somewhat erect ; the bare 

 yellow oesophagus inflated to a- prodigious size, fully half as large 

 as his body, and from its soft membranous substance being well 

 contrasted with the scale-like feathers below it on the breast, and 

 the flexile silky feathers on the neck, which on these occasions 

 stand erect. In this grotesque form he displays in the presence 

 of his intended mate a variety of pleasing attitudes. His love- 

 song is a confused, grating, but not offensively disagreeable 

 tone, — something that we can imitate, but have a difficulty of 

 expressing, — Hurr-hurr-hurr-r-r-r-1ioo^ ending in a deep hollow 



tone. 



