263 
rather than to the hemal nodes of sheep or to supernumerary spleens. 
This was true even of the larger intensely red thoracic nodes found 
after splenectomy, a statement regarding which is found elsewhere.) 
From these observations and experiments I am hence forced to con- 
clude that hemal nodes are not found in the dog. This conclusion 
is in agreement with THOME, RETTERER, RETTERER and LELIEVRE and 
Pınız and also in confirmation of the microscopic investigations of 
the lymph nodes of dogs by RicurER and MERZDORF, — 
The injection of red nodes in the cat led to like results even in 
the case of a very small (2><3 mm.) intensely red node found in the 
mesentery of a cat the great omentum of which contained 59 super- 
numerary spleens. Like results were also contained from the injection 
of nodes in rabbits and guinea pigs in which very red nodes are 
apparently very rare. In the case of young cats and in guinea pigs 
it is not uncommon, however, to inject the peripheral branches of the 
mesenteric vein from mesenteric nodes. Such a result was also ob- 
tained in the case of a pink mesenteric node found in a guinea pig, 
and would seem to suggest that these nodes in young cats and in 
guinea pigs contain sinuses in connection with both the vascular and 
the lymphatic systems. However, a little experimentation will show 
that these results are due to the disproportion between the size of 
the needle and the node and to the exceedingly delicate structure of 
the latter. It was noticed that almost invariably the lymphatics be- 
came injected first and then as the node became distended and its 
architecture disturbed or sufficient back pressure was produced the 
radicles of the vein also became injected. Moreover, injection of these 
mesenteric nodes from the intestine does not result in injection of 
the veins, no doubt, simply because the architecture of the node is 
left undisturbed and because they do not contain lymphatico-venous 
communications. 
Since the writer reported?) the finding of large numbers of super- 
numerary spleens in a comparatively large percentage of apparently 
normal dogs and cats and emphasized?) the fact that the occurrence 
of these has undoubtedly been responsible for misinterpretations in 
the past, it can, to be sure, be urged that these supernumerary 
spleens are hemolymph nodes. It may also be recalled in this con- 
1) Meyer, Jr. of Exp. Zool. 1914. 
2) Meyer, Anat. Rec. Phila. 1913. 
3) Meyer, Jr. of Exp. Zool. 1914 
