44 



CONNECTIVE TISSUES 



Like the other connective tissues, reticular tissue consists of 

 cells, fibres, and ground substance ; the latter, however, is no more 



than a fluid tissue juice which, 

 at least in the lymphoid organs, 

 is identical with the lymph. 

 The fibres are extremely fine 

 and are arranged in slender bun- 

 dles, which jfreely anastomose 

 to form a delicate close-meshed 

 reticulum. Individual fibres 

 can be readily demonstrated in 

 these bundles only after the 

 action of alkalis, digestion by 

 artificial gastric juice, or by 

 other methods of dissociation, 

 yet on careful examination in- 

 dications of fibrillar structure 

 can be seen in the reticulum 

 of fresh tissue and in ordina- 

 ry microscopical preparations. 

 The chemical reactions of the 

 reticular fibres are similar to 

 those of white fibres except that the former are much less readily 

 digested by artificial gastric juice. 



Flattened connective tissue cells clasp the bundles of reticular 

 fibers ; they are mostly found at the intersections of the anasto- 

 mosing bundles. This fact was accountable for the former theory, 

 which regarded reticular tissue as formed by the anastomosing 

 branches of stellate cells. The careful investigations of Carlier * 

 and others have shown the true nature of the lamellar cells and 

 their underlying fibre bundles. 



The fibres of reticular tissue very closely resemble the white 

 fibres of areolar tissue, but differ from them in having a clearer, 

 more highly refractive appearance. Their digestion in pepsin 

 begins only after an interval of two hours, while white fibres are 

 digested in a few minutes ; they also stain less readily than white 

 fibres, and yield reticulin, which differs somewhat from the gelatin 

 of fibrous tissue. The intimate histologic relation between reticu- 

 lar and white fibrous tissue is shown by the fact that the two tis- 

 sues are frequently continuous, 



* 3. Anat, and Physiol., 1895. 



FIG. 47. RETICULUM OF A CERVICAL LYM- 

 PHATIC NODE OF MAN, FROM A THIN SEC- 

 TION FROM WHICH THE LYMPHATIC COR- 

 PUSCLES HAD BEEN PARTIALLY WASHED 

 OUT. 



a, polynuclear lymphatic corpuscle ; &, 

 large mononuclear cell ; c, connective tissue 

 cells of the reticular tissue ; d, fibrous bundle 

 of the reticulum ; e, small mononuclear lym- 

 phatic cell. Hematein and eosin. x 500. 



