=Pancreas.=--The pancreas (Fig. 102, _a_) is a flattened, closely lobulated gland of irregular outline, about twelve centimeters long, varying in width from one to two centimeters. It is bent nearly at right angles at about its middle. One of the halves (_a′_) into which it is divided by its bend lies in the descending limb of the great omentum, and is near the greater curvature of the stomach (_d_) and parallel to it. The free end of this half is in contact with the spleen (_e_). The other half (_a_) lies in the duodenal omentum between the limits of the duodenal U (_c_) and reaches to the bottom of the U. The pancreas has two ducts. The larger =pancreatic duct= (_b_) (sometimes known as the duct of Wirsung) collects the pancreatic fluid from both halves of the gland, the ductlets from each half uniting to make two larger ducts, which then unite near the angle of the gland to make the pancreatic duct. This is short and broad and opens into the ampulla of Vater together with the common bile-duct. The =accessory pancreatic duct= (duct of Santorini) opens into the duodenum about two centimeters caudoventrad of the ampulla of Vater. It is formed by the union of branches which anastomose with those of the pancreatic duct. It is apparently sometimes lacking. [Illustration: FIG. 102.--PANCREAS AND SPLEEN. The œsophagus has been cut and the stomach turned caudad, so that the dorsal surface of the stomach and the ventral surface of the duodenum are seen. _a_, pancreas (_a_, duodenal portion; _a′_, gastric portion); _b_, pancreatic duct; _c_, duodenum; _d_, stomach; _e_, spleen.] =Spleen. Lien.=--The spleen (Fig. 102, _e_) is a deep red, flattened, elongated gland belonging to the lymphatic system. One of its ends, the left, lies against the free end of the gastric half of the pancreas and is broader than the other end. The spleen is curved and is suspended in the descending limb of the great omentum so that it follows the greater curvature of the stomach (_d_). III. RESPIRATORY ORGANS. APPARATUS RESPIRATORIUS. The =organs= of =respiration= consist of the =nasal cavity=, the =nasopharynx=, the =pharynx= (also a food-passage), the =larynx= (also the organ of the voice), the =trachea=, the =bronchi=, and the =lungs=. With them are usually described also the =thyroid= and =thymus glands=.