RETICULAR CONNECTIVE TISSUE. 57 



which cross and join one another at frequent inter- 

 vals, forming a fine meshed network. This net- 

 work of fibres is not flattened to form a membrane, 

 but extends in all directions, like the trabeculae of a 

 sponge. Irregularly scattered over the fibres are 

 flattened nucleated cells, having the character of 

 endothelium, which sometimes lie at the points of 

 intersection of the fibres, sometimes along their 

 sides, enwrapping them with their transparent 

 bodies. When these cells are in situ upon the fibres, 

 the whole presents the appearance of a mass of an- 

 astomosing, branched, or spindle-shaped cells ; and, 

 as such, the reticular connective tissue has until re- 

 cently been regarded, erroneously, however, as is 

 shown by the fact that by appropriate manipulation 

 the flat cells can be entirely freed from the underly- 

 ing fibre-net, leaving the latter intact. The meshes 

 of the reticular tissue are loosely filled, in the lym- 

 phatic nodes, with small, spheroidal cells lymph- 

 cells which, however, seem to have no direct 

 connection with the tissue we are studying, and may 

 be easily removed. 



TECHNIQUE. 



Section of the Lymphatic Node of Dog, Treated with Osmic 

 Acid. One of the mesenteric or cervical nodes is re- 

 moved from a recently killed dog, and a hypodermic 

 syringe being partially filled with one-per-cent. solution of 

 osmic acid, the canula is thrust into the node, and 



