THE GREAT WHITE HERON - . 
121 
covering nearly the entire surface of the proventriculus and stomach, and 
extending under the intestine, being in one place 9 twelfths thick. 
On entering the thorax the oesophagus immediately enlarges to 2£ inches, 
and gradually increases to 3, which is the greatest breadth of the proven- 
triculus, a b c. The stomach, c p e, is a very large round sac, 3 inches in 
width, a little compressed, with roundish tendons, p, 1 inch in diameter; its 
muscular coat extremely thin, and formed of very slender fasciculi ; the 
inner coat soft and smooth. The proventricular glands form a complete belt, 
1£ inches in breadth, at the upper part of which are numerous irregularly 
dispersed very large apertures of mucous crypts. The pyloric lobe of the 
stomach, e, is globular, 9 twelfths in diameter. The aperture of the pylorus 
li twelfths in diameter, without valve. The intestine, e fj k, doubles in 
the usual manner, to form the duodenum, efg , at the distance of 6 inches, 
then proceeds to the right lobe of the liver, bends backward, and is con- 
voluted, with 18 turns, terminating in the rectum above the proventriculus; 
its length 7 feet 10 inches; the width of the duodenum 34 twelfths, that of 
the rest of the intestine pretty uniformly 3 twelfths, a little narrowed 
towards the rectum, which is 5J twelfths long, and at its commencement 
forms a single coecum, i inch long, and 3 twelfths in width. The average 
width of the rectum is 5 twelfths, and it terminates in a globular cloaca, 
j k, 1 inch 10 twelfths in diameter. 
Trachea 22 inches long, considerably flattened, 5 twelfths in breadth at 
the upper part, 4f twelfths at the middle, and lastly contracting to Si 
twelfths. The rings cartilaginous, 270, the last 4 dimidiate. The right 
bronchus has 25 rings, the left 28; they are wide and compressed. There 
is a pair of cleido-trachealjnuscles, passing from the thyroid bone to near 
the middle of the furcula. The lateral muscles are thin and slender at the 
upper part, at the lower part thicker and expanded over the whole surface 
before and behind ; the anterior part gives off the sterno-tracheal, at the 
distance of 9 twelfths from the last ring, and the posterior part passes in 
the form of a compact slip, to the last half ring. 
V OL. YI. 
17 
