LYMPHATIC AND VASCULAR RELATIONS 
29 
here and there where small gaps are found, the injection mass of India 
ink is always retained by a very definite wall. The existence of discon- 
tinuities in the walls of the lacunae can, however, also be demonstrated 
microscopically, and is further proven by the escape of some of the in- 
jected pigment or gelatine mass into the surrounding lymphatic tissue in 
specimens in which extravasations can be excluded because they were 
injected under conditions of a free outflow. This is true no matter how 
carefully the injection has been made. In many places a communication 
of the lacunae with the surrounding parenchyma is further suggested by 
the arrangement of the lymphocytes and erythrocytes in portions of 
empty or partially empty lacunae. In some instances a number of lym- 
phocytes and blood corpuscles are so arranged as to suggest that they 
are entering the lacunae from the parenchyma. The peculiar disposition 
of these cells may be a purely accidental one, to be sure; but the com- 
parative frequency of these very suggestive cellular arrangements would 
seem to imply that this is not the case. If these appearances were due 
to damage done to the specimens, it would be impossible to explain why 
the walls of the lacunae always curve gently outward and disappear 
among the surrounding lymphocytes, rather than ending abruptly and 
projecting into the interior of the lacunae and giving the appearance of 
torn ends. Moreover, there is nothing in the distribution of the pigment 
that suggests an explosive rupture, such as is frequently seen in case of 
extravasations. 
It is to be remembered in this connection, to be sure, that since con- 
siderable quantities of erythrocytes are frequently found in the paren- 
chyma and sinuses of lymph nodes, these must have penetrated not only 
the walls of the blood vessel but those of the lymph sinuses as well, 
in so far as they did not enter the latter through the afferent lymphatics. 
However, there is a marked difference in appearance of the parenchyma 
of hemorrhagic lymph nodes and typical hemal nodes ; and no matter 
how the presence of erythrocytes in lymph nodes may be explained, it 
seems highly improbable to me that their presence in hemal nodes can 
be similarly explained. Helly concluded that hemorrhages are respon- 
sible for red lymph nodes, while v Schumacher reiterated with increas- 
ing emphasis that in both hemorrhagic lymph nodes and hemal nodes 
the erythrocytes likely enter the sinuses and the parenchyma through 
places in the walls of veins and capillaries which have been weakened by 
the passage of lymphocytes. Neuman thought the walls were weakened 
by disease, v Schumacher also explained the presence of extravasations 
of injection mass in the parenchyma of lymph and hemal nodes in this 
