MIXED NODES 
53 
a dog or dogs — and what matters it whether the attacking agent is a 
dog, a disease, or an experimenter? — these lymph nodes had been con- 
verted into hemal nodes. In a second sheep similar conditions were 
found, and similar results obtained. 
In addition to small quantities of lymphatic tissue intermixed with 
blood and pigment, some of the apparently mixed nodes found in sheep 
contain extremely large connective tissue septa and trabeculae, and the 
walls of some of the arteries are many times the ordinary thickness. 
These connective tissue septa are rarely so thick and so extensive that 
they could be seen with the unaided eye, to divide a section of a node 
4-6 mm. in size into more or less distinct portions. Sometimes, also, 
large masses of connective tissue lay here and there under the cap- 
sule, although not continuous with it. In other instances, although 
not evident to the unaided eye, the total amount as well as the relative 
proportions of the connective tissue were smaller than usual, and located 
mainly in the center of the node. Frequently, also small numbers of 
erythrocytes and lymphocytes were scattered about miscellaneously in 
the connective tissue septa. 
The arteries with greatly thickened walls were found almost exclu- 
sively in areas very largely devoid of lymphocytes and erythrocytes. No 
sclerotic or atheromatous changes were seen. The intima was normal or 
practically so, and the thickening of the wall was due entirely to an in- 
crease in thickness of the muscular, and chiefly of the adventitial coats. 
Although slight variations in staining power were observed, this thicken- 
ing of the wall was probably of no significance with respect to the char- 
acter of the node, even if it was correlated with its functional activity. 
Many of the erythrocytes scattered about in these depleted areas 
showed degenerative changes ; but in those portions of the sections of 
the node which had more the appearance of hemal nodes and where they 
were more numerous, they were better preserved. These degenerating 
erythrocytes often lay in groups, which sometimes formed a more or less 
compact mass around leucocytes. Only small, compact masses of lymph- 
ocytes were contained in the depleted portions, but their number increased 
toward the denser portions of the node, until the inter-follicular areas 
looked not unlike splenic tissue because of the intermixture of blood and 
lymphocytes. Between these denser portions of parenchyma small num- 
bers of lymphocytes were also scattered about among certain oxyphile 
cells and erythrocytes; and while follicles were found in the empty por- 
tions, they were common and frequently large in the non-depleted por- 
tions. In these areas the connective tissue septa were, as a rule, consider- 
