THE STBUCTUKE AND GENERAL CHARACTER OF PIGEONS. 



9 



mandible is much narrower than that of the lower. This is most readily 

 observed in a dried skull or in a very young nestling. This peculiarity of 

 structure is important, as it is intimately connected with the mode of nourish- 

 ment of the young bird. 



HO. V. — DIGESTIVE ORGANS OF THE PIGEON. 



a. Boak ; b c. Gullet ; d e. Crop ; fg. Proventriculus ; I. Gizzard ; h i j k. Muscles of gizzard ; mn op q. Intestines ; 



r. Vent. 



The gullet c is wide and opens into a crop d e : this is equal on both sides, unlike 

 that of the fowl. From the back part of the crop, a tube proceeds through the 

 opening at the fore part of the chest into the interior of the body ; this enlarges 

 somewhat before reaching the gizzard, and is termed the proventriculus or fore 

 stomach ; it is furnished with glands which secrete the true gastric or digestive fluid. 

 The gizzard itself is strong and muscular, lined with a thick dense leathery cuticle, 

 and capable of grinding down the food with great rapidity, when aided by the 

 sharp-edged stones and grains of sand swallowed by the bird. The intestinal tube 

 which receives the ground food is upwards cf three feet in length, and is remark- 



