CELLULAR ELEMENTS OF THE GROUND-SUBSTANCE. 13 



Omitting at present everything except the cellular elements of 

 the ground-substance, let us direct our attention to the very smallest 

 isolated patches recognisable as such under the microscope, and let 

 us anticipate that there are no capillary blood-vessels in them, and 

 that the ground-substance is perfectly unstained. The first thing 

 that strikes one are brownish-coloured structures of an irregular shape, 

 that is to say, structures which contain larger and smaller brownish 

 granules ; in most of them an ovoid sharply-outlined nucleus, some- 

 times with a nucleolus, or a constricted nucleus, or even a few small 

 nuclei, are to be seen. These brownish cells are of a different size, but 

 always much larger than colourless blood corpuscles. Their shape is 

 irregular, as has been already stated : their body is beset with a 

 variable number of smaller or larger blunt or roundish prominences. 

 Some of these cells are sharply defined, others are on one side more or 

 less distinctly continuous with the basis on which they lie. It is 

 clear that they correspond, as regards shape, to migratory cells. Be- 

 sides these cells, there is to be found a limited number of small 

 granular corpuscles, with one or two small nuclei, which are perfectly 

 like lymphoid corpuscles. In some places they are in such a close 

 connection with the above-mentioned large cells that they resemble 

 knobs which are in a state of separation from them. 



As we have already mentioned, the ground-substance is unstained. 

 In it we find a network of a finely granular substance, which is stained 

 slightly yellowish. This network consists of large plates, connected 

 with each other by shorter or longer tracts of different breadth. In 

 the plate-like enlargements one recognises a sharp-outlined oblong 

 nucleus, with one or two nucleoli, or a constricted nucleus, or a nucleus 

 which has almost divided into two. In the latter instances, the 

 granular matrix is darker stained in the immediate neighbourhood of 

 the nuclei. I will refer the reader to Fig. 30, which represents such 

 a small patch : a represents the network of the finely granular sub- 

 stance (as this network is represented only in one layer, all of the 

 processes which join the plate-like enlargements are not represented 

 in the figure) ; b represents the above-mentioned irregular-shap cl. 

 large, coarsely granular cells. It is evident from this figure that we 

 have before us a network of branched, more or less flattened, cells, 



