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 

 trabecula? are larger, and they form there a continuity 

 with the connective tissue of the hilum. They are 

 the earners of the large vascular branches. The 

 trabeculre 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 

 after it is given 



^ WWH1 a larger 

 QHC WC find it 



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 trabeculse are 

 filled up with the parenchyma. This consists of two 



Fig. 131. From a Section through the 

 Pulp of the Spleen of the Pig. 



a, Last outrunners of the muscular traberuhr ; 

 //, the flattened cells forming; the honeycombed 

 matrix of the pulp; in the meshes of this 

 matrix are contained lymphoid cells of various 

 fizes. (Atlas.) 



