226 



ELEMENTS OF HISTOLOGY. [Chap. xxix. 



deep part of the capsule contains bundles of non-striped 

 muscular tissue forming plexuses. In man the bundles 

 are relatively thin, but in some mammals e.g., 

 dog, pig, horse they are continuous masses arranged 

 sometimes as a deep longitudinal and a superficial 

 circular layer. 



In connection with the capsule are the trabeculce 

 (Fig. 130). These are microscopical, thicker or thinner 

 cylindrical bands branching and anastomosing, and 

 thus making a framework in which the tissue of 

 the spleen is contained. Towards the hilum the 

 trabeculse are larger, and they form there a continuity 

 with the connective tissue of the hilum. They are 

 the carriers of the large vascular branches. The 

 trabeculse in the human spleen consist chiefly of 

 fibrous tissue with an admixture of longitudinal non- 

 striped muscular 

 tissue. This is 

 more pronounced 

 in the dog, horse, 

 pig, guinea-pig, in 

 which the trabe- 

 culse are chiefly 

 composed of non- 

 striped muscular 

 tissue. Following 

 a small trabecula 



JFig. 131. From a Section through the after it IS given 

 Pulp of the Spleen of the Pig. , & 



a, Last outrunners of the muscular trabeculas ; Ott tr Om a larger 



6, the flattened cells forming the honeycombed nnp WP finrl it, 



matrix of the pulp: in the meshes of this One > We Dn( \ 1T} 



rnatrix are contained lymphoid cells of various branching into 



still smaller ones, 



which ultimately lose themselves amongst the elements 

 of that part of the spleen tissue called spleen pulp 

 (Fig. 131). 



The meshes of the network of the trabeculas are 

 filled up with the parenchyma. This consists of two 



