1084 
DR. H. WATNEY OH THE MINUTE ANATOMY OF THE THYMUS, 
most of the cells and their processes will he shaken away (as in Plate 87, fig. 26), only 
those remaining which are attached to the blood vessels, and thus have a firm support. 
The nuclei of the connective-tissue-corpuscles, forming the network, and of the endo¬ 
thelial cells of the blood vessels (see Plate 87, figs. 28 and 25) and the nuclei of the 
cells forming the capsule, are all similar in size and appearance ; and in specimens 
stained in indigo-carmine and carmine, the branched connective-tissue-corpuscles, the 
blood vessels, and the connective-tissue threads, all stain of a red colour, and not like 
the reticulum, of a blue-green. 
It will be seen from the foregoing description, and from Plate 87, figs. 25 and 27, 
that in the cortex there are two hinds of retiform-tissue; one (with small meshes) which 
we have called a reticulum, formed of fine fibres with thickened nodal points ; and the 
other, which we have called a netivork, composed of branched connective-tissue-corpuscles . 
These are not to be considered as identical, nor as arising the one from the other, but 
are two distinct meshes lying one within the other. 
The Tissues composing the Medullary portion of the Follicle. 
The network of branched connective-tissue-corpuscles of the cortex is continuous 
with a network of branched cells in the medulla, but there is a considerable difference 
in the two networks (compare Plate 87, fig. 25, with Plate 86, fig. 18, and Plate 93, 
fig. 78). In Plate 86, fig. 18, the cells are larger than in Plate 87, fig. 25 ; they are 
joined together, not by very delicate, but by coarse, sharply-defined cell processes ; and 
the body of the cell is also much thicker. Again, the spaces enclosed by the cell pro¬ 
cesses are not of an indefinite polygonal area, but are sharply defined, and nearly 
spherical (see Plate 93, fig. 78). 
The connective-tissue-corpuscles forming the network are not, however, always met 
with as branching cells, but at times are close together, and then they have no pro¬ 
cesses, bat lie side by side like an endothelium (see Plate 88, fig. 30, cY, and Plate 89, 
fig. 45 A, B, C). These latter will be called epithelioid cells. Further, in some places, 
the cells are so closely approximated that no trace of cell-division can be seen; and 
here we find masses of protoplasm, containing three, four, or numerous nuclei, not 
differentiated into cells (see Plate 88, fig. 30 ; and Plate 90, fig. 54). 
The reticulum, which is so marked a feature of the cortex, is also found to a slight 
extent in the medulla (see Plate 88, fig. 31; and Plate 93, fig. 83), but in this part of 
the follicle it does not enclose all the other tissues in its meshes. It is only seen here 
and there, and gives the impression which would be made if the cells which it 
originally enclosed had multiplied, the reticulum itself not having increased; so that 
the reticulum is only seen at intervals, among the connective-tissue-corpuscles or the 
epithelioid cells. 
The medulla, therefore, contains a network, formed either (1) of branched connective- 
