120 



On the inside of the gizzard, in the Anas americana, opposite 

 to the centre of each muscle, is a smooth, hard, and almost bony 

 plate, one of which has its thickest edge uppermost, and the other 

 the reverse, so that they present their surfaces diagonally, as 

 regards the plane of motion, though applying their opposite sur- 

 faces very exactly to each other. These plates are of an oblong 

 shape, |- of an inch in length, and f across. 



Dr. Cabot also stated that he had dissected a male of Tetrao 

 cupido ; and gave the measurement of some of the internal 

 organs, viz. : ^ 



Tongue. Length, to tip of os hyoides, 2^ ; to opening of 

 larynx, ^ ; to base, f . 



(Esophagus. Length, to crop, 5 ; diameter of upper part, 

 which is very dilatable, IJ ; length to proventriculus, 8^. 



Proventriculus. Length, l^ ; thickness, -^^. 



Gizzard. Longest diameter, 2f ; shortest diameter, 1 ; at 

 right angles with the longest diameter. If ; lining membrane of 

 gizzard very tough and horny, and marked by longitudinal rugae, 

 its muscular parietes about J inch thick ; filled with half-digested 

 corn, rye and other seeds, mixed with fragments of stone and 

 sand. 



Intestinal canal. From gizzard to anus, length, 70. 



Coeca. Length, 23 ; opening into intestine, 5 from anus ; 

 diameter of upper part, flattened out, f ; its diameter larger than 

 that of the intestine in its whole length, except in the cloaca and 

 the upper part of oesophagus. 



Crop. Diameter, when flattened out, 3. 



Liver. Length of right lobe, 2|- ; in diameter, l^ ; length of 

 left lobe, 2 ; in diameter, 1|. 



Kidneys. Length, nearly 2. 



Testicles. In length, f^- 



Heart. In length. If; diameter, If. 



Trachea. To bifurcation, not stretched, 6 ; do., stretched, 6f . 



Bronchi. In length, |. 



Dr. C. T. Jackson read the results of a chemical analysis 



I The measurements are in inches and parts of an inch. 



