52 
HEMOLYMPH NODES OF THE SHEEP 
dent, of course, that congestion or hemorrhage or diapedesis in an organ 
does not change the essential morphological identity of that organ. 
Upon microscopical examination most of these apparently transi- 
tional forms were found to contain no lacunae of Weidenreich (true 
venous sinuses) or large blood islands or blood spaces. In addition to 
portions of the parenchyma which looked like splenic tissue devoid of 
Malpighian corpuscles, or which, on the contrary, consisted of an almost 
solid mass of lymphatic tissue, they contained areas in which a great 
deal of golden pigment, and more rarely many oxyphile cells, were pres- 
ent. The partly depleted nature of certain of these nodes, and especially 
the presence in them of much brassy pigment and the occurrence of 
abundant phagocytosis, gave a very peculiar appearance to a section. 
Because of the open character of the parenchyma, they simulated lymph 
nodes much more closely microscopically than hemal nodes. Since 
phagocytosis is a very noticeable feature in these specimens, it does not 
seem impossible, to me, that Lewis's [14] observations regarding the 
relative, frequency of phagocytosis in the spleen to that in the hemal 
nodes, was based on observations on this type of lymph node. This 
supposition gains in probability by the observations made on patho- 
logical human lymph nodes by Warthin and Meek, to the effect that 
the degree of pigmentation varies with the amount of hemolysis ; and also 
by the observations of v Schumacher regarding the comparative infre- 
quency of phagocytosis in hemal nodes. Meek also speaks of the occur- 
rence of "yellow or light brown pigment, usually confined to the sinuses 
though rarely found in the germ centers." Meek also found that even 
in these pathological human nodes the reactions for free iron were very 
variable, and in the majority of cases not obtained, though occasionally 
the presence of a large amount of free iron could be established. These 
findings of Meek are in entire accord with what was found by the writer 
in intensely congested, apparently hemal nodes, found along the common 
iliac vessels in the carcass of a sheep which had been seriously torn in 
the gluteal region by dogs, and in another which died of septicaemia. 
The first sheep was bled to death after necrosis had set in at the site of 
injury, some days after having been attacked. At necropsy it was found 
that practically all the pelvic and prevertebral lymph nodes were hemal 
in color, and could probably not have been identified positively by micros- 
copic examination alone ; yet by injections it was easily shown that they 
were lymph nodes in direct connection with the lumbar lymphatics and 
the thoracic duct. The dilated lymphatics going to these nodes were 
plainly visible, and were tinged with blood. It would be ridiculous, to 
be sure, to assume that simply because this animal had been attacked by 
