PHYSIOLOGICAL ANATOMY OF THE SPLEEN. 



415 



the capsule of Malpighi and the fibrous coat at right angles, very soon branch, 

 interlace,' and unite with each other, becoming smaller and smaller, until 

 they measure ^Ju-'to -fa of an inch (0*1 to 0*42 mm.). This fibrous net- work 

 serves as a support for the softer and more delicate parts. 



Malpighian Bodies. These bodies are sometimes called the splenic cor- 

 puscles or glands. They are rounded or slightly ovoid, about -fa of an inch 

 (O5 mm.) in diameter, and are filled with what are thought to be lymph- 

 corpuscles, and free nuclei. The Malpighian bodies have no investing mem- 

 brane. With this difference, they resemble in structure the solitary glands 

 of the intestine. Both the cells and the free nuclei of the splenic corpuscles 

 bear a close resemblance to cells and nuclei found in the spleen-pulp. The 

 corpuscles are surrounded by blood- 

 vessels which send branches into 

 the interior, to form a delicate, capil- 

 lary plexus and by what is thought 

 to be a lymphatic space or sinus. 



The number of the Malpighian 

 corpuscles in a spleen of ordinary 

 size has been estimated at about ten 

 thousand (Sappey). They are readi- 

 ly made out in the ox and sheep 

 but are frequently not to be discov- 

 ered in the human subject. The 

 occasional absence of these bodies 

 constitutes another point of resem- 

 blance to the solitary glands of the 

 small intestine. 



The Malpighian bodies are at- 

 tached to arteries measuring -fa to 

 -fa of an inch (O32 to 0-42 mm.) or 

 less in diameter (Sappey). They are often found in the notch formed by 

 the branching of an artery, but they usually lie by the sides of the vessel. 



Spleen-pulp. The spleen-pulp is a dark, reddish, semi-fluid substance, its 

 color varying in intensity in different specimens. It is so soft that it may be 

 washed by a stream of water from a thin section, and it readily decomposes, 

 becoming then nearly fluid. It is contained in the cavities bounded by the 

 fibrous trabeculae, and it contains itself microscopic bands of fibres arranged 

 in the same way. It surrounds the Malpighian bodies and contains the termi- 

 nal branches of the blood-vessels, nerves and lymphatics. Upon microscopi- 

 cal examination, it presents free nuclei and cells like those described in the Mal- 

 pighian bodies ; but the nuclei are here relatively much more abundant. In 

 addition are found, red blood-corpuscles, some natural in form and size and 

 others more or less altered, with pigmentary granules, both free and en- 

 closed in cells. 



Blood-vessels, Nerves and Lymphatics of the Spleen. The quantity of blood 

 which the spleen receives is very large in proportion to the size of the organ 



FIG. 139. Malpighian corpuscle of the spleen of the 



caffcadiat). 



A, artery around which the corpuscle is placed ; B, 

 meshes of the pulp, injected ; c, the artery of the 

 corpuscle ramifying in the lymphatic tissue. 

 The clear space around the corpuscle is the lymphat- 

 ic sinus 



