

VARIETIES OF CONNECTIVE TISSUE. 67 



The reticulum of the lymphoid organs contains not only cells 

 in its areolse, but also supports blood-vessels, and the trabe- 

 culsQ unite upon the external surface of the vessels to form a 

 kind of Tunica adventitia. And hence in the capillaries, this 

 layer was designated by His the Adventitia capillaris. The 

 trabeculse of the latter must not be confounded with the pro- 

 cesses given off from the wall of the vessel itself, which, as they 

 develop, present in the part lying at some distance from the 

 artery, the appearance of a solid trabecula, but which gradually 

 become hollow as they approximate the artery to which they 

 are attached. 



The reticulum does not, in all instances, nor in all parts of 

 the organs above named, present the characters of such a net- 

 work as we have described. When developed to a greater 

 extent, it passes into a network of non-nucleated trabeculse* 

 which are of a far more rigid 'nature, and often appear con- 

 siderably expanded. A trellis-work of this kind may, from 

 its resistance to acids, easily be mistaken for the elastic fibrous 

 networks we shall hereafter describe, and which have a similar 

 plexiform arrangement. But as the latter are distinguished 

 from the fibrillar connective tissue by the circumstance that 

 the connective tissue fibres are never branched and never form 

 networks, though their fibrous bundles frequently present a 

 net-like arrangement; so is this also distinguished from the 

 elastic fibre networks by the circumstance that, unlike these, it 

 is incapable of resisting the action of a solution of soda. It has 

 been previously stated, that reticula, similar to those found 

 in the lymphatic glands, are found also in other places. 



A wide-meshed network of trabeculse is found consti- 

 tuting a kind of investing layer, winding around the bundles 

 of the fibrillar connective tissue hereafter to be described. In 

 consequence of the appearances to which this gives rise, when 

 the fasciculi in question swell up under the influence of acetic 

 acid, it has led some to admit the presence of a structureless 

 sheath surrounding each fasciculus. If have myself depicted 



* Henle, Zcitschrift fur Rationelle Medicin, Band Viii., 3 JL, p. 201. 

 Eckhard, loc. cit. 

 J Wiener Sitzungsberichte, Band xxx., p. 71, fig. 12. 



