LYMPHATIC AND VASCULAR RELATIONS 
17 
node. To be sure, the choice of nodes is of primary importance, and no 
one can be positive that he has selected a hemal node if he fails to inject 
the vein or lymphatics. Besides, no one will doubt that a venous radicle 
must have been penetrated by the needle or its wall penetrated by the in- 
jection mass, if the vein leaving the node is filled ; but after examining 
numerous nodes which had been injected by puncture, I must entertain 
the gravest doubts as to the possibility of determining the exact point 
of puncture of a venous lacunae. For even the smallest needle or capil- 
lary glass tube bears a marked disproportion to the size of the numerous 
venous radicles in a node. Besides, it would be likely to pierce so many 
— or none — for most of the hemal nodes are small, as v Schumacher 
rightly emphasizes. Hence locating the exact point of puncture of the 
wall of a particular venous lacuna through which the injection mass is 
supposed to have entered, must be open to serious error, even if possible. 
Moreover, veins are not always present within a node ; venous lacunae or 
sinuses take their place frequently. 
It was generally very easy to see the injected fluid pass from the 
hemolymph node to the vena cava, pushing the blood in the vein leaving 
the node before it. As more fluid was injected, a steady stream, some- 
times inter-mixed with blood and bubbles, could be seen passing to the 
vena cava or the iliac veins. Frequently the injected fluid would pass 
in a somewhat roundabout way to reach its destination in the large veins ; 
and occasionally it would leave the node in two directions from the same 
or from different points. Clamping of the vein on its way to the vena 
cava led to rupture of the node upon further injection, but not to the in- 
jection of lymphatics. Anastomosing veins would occasionally become 
filled with fluid; but several times only did an adjacent or distant node 
seem to change its color very slightly. For a time this inability to 
inject one node from another in the fresh hanging carcasses was very 
puzzling, for it was evident that the veins from several nodes not infre- 
quently joined on their way to the vena cava. Besides, it will be recalled 
that Weidenreich [37] reported that it was easy to inject a node from a 
neighboring one. This apparent contradiction of Weidenreich's results 
was emphasized further by the fact that it was never possible to inject 
secondarily smaller hemolymph nodes which lay in actual contact with 
the larger ones, from which the injection was made. This was true, even 
when it was afterwards found by injection of differently colored fluids 
from the individual nodes concerned that they were drained by branches 
of the same vein. Naturally the fact that small veins draining hemolymph 
nodes are usually full of blood, suggested that the failure to inject one 
