THORAX AND ABDOMEN OF THE HORSE 138 



amount of interlobular tissue, with the result that the lobules are not 

 very sharply bounded, and the liver tissue is comparatively friable. In 

 certain pathological conditions, not uncommonly met with in old dissec- 

 tion-subjects, the interlobular septa are exaggerated. 



Under the serous investment provided by the peritoneum, there is a 

 thin fibrous capsule that may be traced into the interior of the organ at 

 the porta. The various structures that enter or leave by the porta 

 (portal vein, hepatic artery, bile-duct, &c.) are thus provided with a 

 fibrous sheath that divides with the ramification of the vessels, &c. 

 The sheath, as well as the capsule on the exterior, is continuous with 

 the interlobular septa. 



CEsophageal part of 

 mucous membrane. 



-Opening of cesophagus. 

 ^. Margo plicatus. 



Duodenum. 



Diverticulum duodeni. 

 Sphincter pylori. 



Glandular part of mucous 

 membrane. 



Fig. 60. — Longitudinal section of the stomacli. 

 Structure of the spleen. — Under the peritoneal covering of the 

 spleen there is a fibrous tunic, from which irregular branching trabecidcB ^ 

 proceed into the interior, where, by the union of their branches, they 

 produce the sponge-like framework of the organ. In the meshes of the 

 sponge is the splenic j)'^lp, composed very largely of blood, and there- 

 fore resembling a blood-clot. Certain small, pale, rounded areas in the 

 pulp are the splenic corpuscles of Malpighi,- consisting of rounded 

 masses of lymphoid tissue intimately associated with the wall of the 

 smaller branches of the splenic artery. 



Dissection.— li the subject is a female, those reproductive organs 

 that are contained within the abdomen must now ])e examined. 



' Trabecida, dim. of trabs [L.], a beam. 

 - Marcello Malpighi, an Italian anatomist, 1628-1694. 



