504 



THE DIGESTIVE APPARATUS IN MAMMALIA. 



already known as proceeding to the colon, and in its passage becoming attached 

 to the splenic fissure, whence it extends over the surface of the organ to form its 

 serous covering. 



Structure, — The tissue of the spleen has a violet-blue colour, sometimes 

 approaching to a red liue ; it is elastic, tenacious, and soft, yields to the pressm-e 

 of the finger, and retains its imprint. Enveloped externally by the peritoneum, 

 its substance includes a fibrous framework, splenic pulp, MaJpighian corpuscles, 

 vessels, and nerves. 



Serous membrane. — This is spread over the whole surface of the organ, except 

 in the fissure of the anterior border. Its internal face adheres most intimately 



Vis. 299. 



STRUCTURE OF THE SPLEEN (DIAGRAMMATIC). 



A, Artery; V, vein. 1, Splenic trabeculse; 2, finer trabeculse; 3, reticulum of the splenic pulp; 

 4, lymphoid infiltration into the sheath of the arteries; 5, its continuation with a Malpighiaa 

 corpuscle; 6, membrana propria; 7, sheath of the vein; 8, recticulum of the splenic pulp; 9, 

 termination of the fibrillar sheath of the capillaries; 10, tuft of arteries ; 11, arterial capillaries; 

 12, their opening into the intermediate tracts of the pulp; 13, veins; 14, venous capillaries; 15, 

 part of the pulp containing the remains of cells; 16, Malpighian corpuscle attached to (17) an 

 artery, seen in a section perpendicular to the axis of the vessel. 



to the proper tunic of the spleen. It is only an expansion of the serous bands 

 which limit the movements of the viscus. 



Fibrous framework. — Under the peritoneal membrane is a thick, resisting, 

 fibrous tunic, roughened and granular on its exterior, and sending from its deep 

 face into the interior of the mass a multitude of prolongations called trabec^ds, 

 which cross in all directions, forming a cellular network, in the numerous naiTOW 

 meshes of which are the other elements of the organ. In washing out a morsel 

 of spleen in a jet of water, the latter are removed, and the outlines of this 

 fibrous structure are fully exposed. If a stream of water be passed tlirough the 



