The organ occupying the right of the following cut, is the spleen. It is a soft vascular organ of a purplish color. It is not a true gland, as it has no duct.

The shape of the spleen is irregular and variable, but it is generally the section of an ovoid, with a convex surface resting against the diaphragm, opposite the ninth, tenth, and eleventh ribs, and a convex surface directed towards the stomach.

It varies in size more than any other organ in the body. It is generally five inches long and three wide, and weighs from five to seven ounces. The proper substance of the spleen is a soft, pulpy mass, of a reddish-brown color, resembling grumous blood. Its office in the economy is not well understood, but is evidently concerned in the blood-depurating process. It is numerously supplied with lymphatics. The long and flat gland lying between the spleen and duodenum, in the left of the cut, is the Pancreas, or sweet-bread. It is of a light-pink color, and is about seven inches long. Its right extremity, or head, is much the thickest part, and is often called the lesser pancreas. Its left extremity gradually diminishes in breadth until it touches the spleen. The superior edge has a groove for the passage of the splenic artry. Its structure is conglomerate. Its excretory duct is called the duct of Wirsungius.

Its secretion is somewhat similar to saliva, hence it is often called the abdominal salivary gland. Its secretion contains a larger amount of solid matter than the saliva, and assists in the process of digestion.