i6 
HEMOLYMPH NODES OF THE SHEEP 
be discussed especially in a separate article on this subject; but it may 
here be noted that the conclusion that a true hemolymph node is merely 
a lymph node devoid of lymphatic vessels and sinuses, is only possible 
upon a fundamental misconception of the real character of the vascular 
circulation of true hemal nodes. 
These considerations at once raise the question of the relation be- 
tween hemolymph nodes and the lymphatic system. In order to deter- 
mine whether a direct connection exists between them, injection methods 
seemed to offer the best and perhaps the only positive proof. Since an 
abundant supply of material could be found in the carcasses of sheep, 
the abattoir again suggested itself as an especially good field for this 
work. Hence many hundreds — thousands — of injections were made 
directly into the nodes upon the fresh carcasses. Occasionally this was 
within ten minutes or a quarter of an hour after death. The results ob- 
tained by means of puncture injections with a hypodermic syringe into 
the nodes practically undisturbed in situ in the lumbar region, were sur- 
prisingly uniform. As node after node on the hanging carcasses was 
punctured and injected, the invariable result of the injection of a few 
drops of methylene blue, Prussian blue, India ink, etc., was the almost 
immediate appearance of the fluid in the vena cava, or occasionally in the 
common iliac veins. Since the appearance of even a fraction of a drop 
of the colored solutions or suspensions quickly became evident in the col- 
lapsed veins, it was, to be sure, an easy matter to decide between suc- 
cess and failure. To avoid error many hundreds of injections were made 
into nodes of various sizes, shapes, colors, and positions in the abdominal 
and thoracic cavities of sheep from a few weeks to four or five years old. 
By far the greatest number of these injections were made on the lumbar 
group, however. 
v Schumacher, who agreed with Weidenreich and the writer as to 
the injections of the vein by means of puncture of the node, however, 
emphasized the fact that he obtained such a result by no means in every 
case, but only when one of the intra-nodal veins was pierced. In numer- 
ous instances v Schumacher found that only the sinuses in the interior 
of the gland were filled, and whenever the vein leaving the node was in- 
jected v Schumacher says he could always tell by serial sections that a 
vein in the interior of the gland had been punctured by the needle, so 
that the injection mass could pass directly into the large collecting veins 
at the hilus. 
I am at a loss to account for v Schumacher's failure to inject the 
veins of hemal nodes in practically all cases by means of puncture of the 
