A microscopic study of the liver of the fowl shows a compact mass of liver cells polyhedral in shape, with large nuclei (Fig. 38, _A_). The liver tissue differs from that of mammals in that there is no clearly outlined lobular arrangement; neither is the outline of the individual cell so well marked. The parenchymatous portion is made up of columns of liver tissue. These columns anastomose and show narrow channels between. They are best seen in the young chick. _Function._—One of the functions of the liver is to secrete bile. A _gall-bladder_, which receives part of the bile secreted by the right lobe of the liver, is located on the posterior face of this lobe. Extending from this gall-bladder there is a duct, the _cystic duct_, which empties into the small intestine toward the extremity of the second branch of the duodenal loop. Another duct called the _hepatic duct_, proceeds directly from the two lobes of the liver and empties into the intestine just in front of the cystic duct. =The Pancreas= (Fig. 31, No. 17). _Location and Shape._—The pancreas, an organ lying in the duodenal loop is a yellowish-white, lobulated gland, elongated in shape. Its average length in fowls of average size is 4.96 inches, and the average weight about 0.008 pound. The pancreas is divided into lobes, which in turn are divided into lobules. _Structure._—The pancreas has a supporting connective tissue. The lobules are made up of small alveolar glands, which are lined with columnar epithelial cells. The ducts leading from the alveoli are small; these unite to form larger ducts in which the epithelium is taller. Between the alveoli throughout the pancreas there are clusters of polyhedral cells which form the _islands of Langerhans_. These islands are said to produce an internal secretion, or hormone, which is absorbed by the blood or lymph capillaries and thus enters the circulation (Fig. 38, _B_). _Function._—The function of the pancreas is to secrete a fluid containing digestive ferments. =The Spleen= (Fig. 31, No. 21). _Location._—The spleen, or lien, lies in a triangle formed by the proventriculus, the liver, and the gizzard. _Shape._—It is a reddish-brown body shaped like a buckeye, is small in size, weighing only about 0.005 pound. _Structure._—The outer surface of the spleen is covered by a reflection of the peritoneum. After this covering is removed, there is observed a firm, white, fibrous layer, the _cortical portion_. This covering sends into the interior small and large trabeculæ, forming a framework and dividing it into acini, or compartments. The spaces are filled with a dark red parenchymatous material called _splenic pulp_. The framework, in both deep and surface portions, are found elastic fibers and smooth muscular fibers.