OBSERVATIONS ON THE STRUCTURE OF THE SPLEEN, 871 
admits only of the theory of W. Miller, Frey, and others, 
2.e. that the venous radicles represent merely a labyrinth of 
spaces in the splenic parenchyma. 
The question next to be considered is the relation of the 
matrix of the pulp to that of the adenoid tissue of the arterial 
sheaths and the Malpighian corpuscles. Iam in accordance 
with those observers who maintain that the one passes gra- 
dually into the other. I have found very abundant evidence 
for this in the human spleen. Examining attentively the 
peripheral parts of the adenoid tissue, especially in prepara- 
tions which have been previously shaken, it is found that the 
honeycomb of membranes of the pulp is directly continuous 
with the honeycomb of membranous structures forming the 
so-called reticulum of the adenoid tissue ; with the difference, 
however, that in the latter the membranous structures 
become greatly reduced in their size and the meshes assume a 
more uniform aspect. ‘The number of the nuclei of the 
matrix is at the same time reduced to such an extent that 
it becomes quite intelligible why Schweigger-Seidel (‘Vir- 
chow’s Archiv,’ Bd. xxiii, p. 526) altogether questioned 
their existence in the reticulum of the adenoid tissue of the 
Malpighian corpuscles. As in the pulp so also in the 
adenoid tissue nucleated buds are found in more or less 
intimate connection with the matrix ; in the adenoid tissue 
their number becomes very great, and they are in reality the 
well-known lymph corpuscles, many of which have become 
perfectly detached from the matrix. 
In the pulp of the human spleen I find likewise lumps of 
yellowish pigment in smaller and larger groups, chiefly con- 
tained in the small spaces of the labyrinth and also in the 
matrix itself. Occasionally they are included in a cell. As 
was mentioned at the beginning of this paper, it is held 
that this pigment stands in an intimate relation to coloured 
blood-corpuscles, which having been taken up by lymphoid 
cells are broken up into small lumps within these structures. 
It seems to me more probable that the chief process of de- 
struction of coloured blood corpuscles—.e. the production of 
those yellowish lumps—is carried out not in the way gene- 
rally described, 7. e. blood corpuscles being taken up by 
lymph cells, but by the matrix itself exerting that destruc- 
tive influence on the blood corpuscles. In support of this I 
adduce the constant presence of the free pigment lumps in 
the spaces of the labyrinth and in the matrix of the spleen 
of dog; I have seen only extremely few distinct instances 
in the spleen of this animal, where these lumps were con- 
tained in alymphoid cell, And also with regard to the 
