178 MANUAL OF HISTOLOGY. 



by slight variations in the size of the meshes and the fineness of 

 the fibres, the meshes being longer and narrower in the peri- 

 pheral portions of the follicles and in the cords than in the 

 central part of the former. This sort of tissue has received 

 different names : cytogenous tissue (Kolliker), adenoid tissue 

 (His), reticular tissue (Frey, Ranvier). It is, as the latter name 

 implies, a network, the fibres of which run in ev.ery direction, 

 being applied to one another in the same manner as the fibres 

 of the omentum. already described. The nuclei, which are 

 more oval and larger than the lymphoid corpuscles, appear at 

 the junction of fibres, simply rest upon them, and can be re- 

 moved by brushing. They are endothelial cells, and in silver- 

 stained preparations an endothelial layer can be seen to cover 

 the septa, the reticulum of the lymph-passages, and the folli- 

 cles in the same manner that the fine bundles of the omentum 

 are covered ; that is, the spaces between the bundles are no- 

 where covered, but each bundle is wrapped by these cells. 

 This can only be seen after the lymphoid corpuscles that occupy 

 the meshes have been removed by brushing. The endothelial 

 layer is continuous with that of the afferent and efferent lym- 

 phatic vessels, which communicate with the lymph-spaces of 

 the node, as shown by injections. 



According to Klein, the clinical nature of reticular tissue 

 does not correspond to connective tissue proper or to elastic 

 tissue. Filling the meshes of the follicular and cylindrical 

 portions of the lymphoid masses are the lymphoid corpuscles, 

 two or more in each mesh. Lymphoid corpuscles are also 

 found in the investing or lymph-spaces, but they are easily 

 brushed out, while a much longer brushing is required to de- 

 tach them from the other portions. The corpuscles are some- 

 what larger than the colorless blood-corpuscles, though vari- 

 able in size. They possess a single prominent nucleus, which 

 is readily stained by most coloring matters. The amount of 

 protoplasm they possess is small. When examined in a moist 

 chamber at a temperature of 36 to 37 C., some of them ex- 

 hibit amoeboid movements, the small ones having the least 

 protoplasm around their nuclei being most active (Ranvier). 

 Klein states that corpuscles are to be found which are larger 

 than the others, having more protoplasm, and often two nuclei. 

 He considers them in a more advanced stage of development 

 than the others. 



