There is no gallbladder, and the biliary duct enters the duodenum about 6 in.
The principal duct enters the duodenum with the bileduct, and there is often a second small duct opening separately.
In the ostrich, Struthio, the craze of overloading the stomach with pebbles which, when triturated into sand, are not voided, has brought about a dislocation, so that the enormously widened and stretched space between proventriculus and gizzard forms a bag, directed downwards, whilst the gizzard itself with part of the duodenum is rotated round its axis to more than loo°.
In this sense alone quinine is a tonic. The hydrochloric acid of the gastric juice is stated to convert any salt of quinine into a chloride, and it seems probable that the absorption of quinine takes place mainly from the stomach, for when the drug reaches the alkaline secretions of the duodenum it is precipitated, and probably none of it is thereafter absorbed.
Besides the crypts of Lieberkiihn found throughout the intestinal canal, and the glands of Brunner confined to the duodenum, there are other structures in the mucous membrane, about the nature of which there is still much uncertainty, called " solitary " and " agminated " glands, the latter more commonly known by the name of " Peyer's patches."