46 
HEMOLYMPH NODES OF THE SHEEP 
istic of any particular type of node, or that they are confined to any par- 
ticular stage of development. They were present in foetal nodes, in those 
from young lambs, and in those from adult sheep as well. Usually they 
lay somewhat isolated, though rarely a group of three or four was found. 
They varied much in size, a single section of the largest extending half- 
way across the field of a No. 5 ocular and homogeneous immersion (Zeis) 
and through a thickness of 10-50^1; the largest measuring 30x50x30^1 by 
filar micrometer. The protoplasm, which was non-granular, took an eosi- 
nophile stain and was not surrounded by a recognizable cell membrane. 
Rarely a somewhat hyaline border, suggesting degenerative changes, was 
noticeable. The vesicular well defined, apparently separate, nuclei, were 
generally circular or irregularly oval in shape, had a distinct nuclear mem- 
brane, and varied from about 5 to 20 \i in size. When large and single, 
the nucleus was frequently lobed or crenated ; and when multiple, as many 
as six could often be seen without a change of focus, assembled in the 
center or scattered about at random in the protoplasm. The chromatin 
granules in the nucleus were few and small, the nuclear network indis- 
tinct, and mitotic figures or conclusive evidences of amitosis were 
never observed. However, since only a comparatively small number of 
these giant cells could be observed, it would be unjust to over-emphasize 
these facts. Vacuoles were seen only occasionally; but some cells seemed 
crowded with inclusions, some of which simulated erythrocytes and plate- 
lets quite closely ; while still other areas looked like local condensations in 
the protoplasm, which in the stains used suggested areas of degeneration, 
some of which looked not unlike Negri bodies. In some cases these local 
condensations or degenerations which stain a deeper pink are surrounded 
by a clear area or halo, which gives the whole structure a superficial 
resemblance to a nucleated cell ; and in other cases such were actually 
included in the periphery of the protoplasm. 
Plasma cells were found in small numbers in some of the specimens 
only. They were demonstrated most successfully by Unna's polychrome 
methylene blue, after fixation and hardening in alcohol. Preparations 
were also stained according to Ehrlich, Ehrlich and Westphal, and also 
by Unna's polychrome methylene blue followed by orcein ; but the results 
obtained by these stains were not as satisfactory. There was nothing char- 
acteristic about their distribution or structure, for isolated specimens were 
scattered about at random, and were also found in some of the follicles. 
I do not regard their presence as unusual or specially significant, or in- 
dicative of inflammatory changes, for the nodes were normal specimens. 
Mast and iron containing cells were never found, although special 
