196 



MANUAL OF HISTOLOGY. 



In hardened preparations it consists of a fine network of pale, delicately- 

 contoured, and very slight fibrillje, which may be, however, partially ex- 

 panded into membranous processes at points. Here and there we meet 

 with pale oval nuclei in these. The meshes of this framework, measuring 

 0-0226-0-0068 mm., are occupied, in the first place, by lymphoid cells, 

 but also by coloured blood-corpuscles. 



Fig. 187. Reticular connective-substance from the intestinal mucous membrane of the 

 sheep; strongly magnified. 1. Taken from the immediate neighbourhood of a fol- 

 licle, a, transverse section of a follicle of Lieberkiilm ; 6, network; c, lymph-cells. 

 2. Somewhat more remote, a, rounded; 6, elongated, nuclei. 3. At a still greater 

 distance from the follicle, a, tissue of indefinite character; 6, reticular; c, nuclei; 

 d, lymph-corpuscles; , vacant space where a gland had been. 



In pathological processes this kind of reticular substance, also contain- 

 ing lymphoid cells, plays no unimportant part. 



Apart from enlargement of the organs consisting of it, as the lymphatic 

 glands, the tonsils, Payer's patches, and the spleen, we also recognise 

 new growths of the tissue in question in other parts, at the expense of 

 the framework of fibrous tissue, as, for instance, in the liver, kidney, and 

 stomach. 



119. 



We turn now to a formation about which far less is known than of 

 ordinary reticular connective-tissue, namely, the delicate sustcntacular sub- 

 stance of the nervous centres and the retina. That it originates from the 

 middle germinal plate, the source of the other members of this series, appears, 

 besides, doubtful, so that its position among the connective-tissues may re- 

 quire to be altered in consequence. Although long ago the presence of 

 such a framework in the substance of the brain and spinal cord was here 

 and there allowed, it was a long time, nevertheless, before the present views 

 regarding it were generally recognised. Moreover, we are met by the 

 impossibility of drawing any very sharp line between the tissue in 

 question and the nervous form-elements of grey matter. We cannot 

 wonder, then, that Bidder and his pupils suppose this substratum of con- 



