OBSERVATIONS ON THE STRUCTURE OF THE SPLEEN, 3865 
reticulum of delicate fibrils analogous to the reticulum of the 
adenoid tissue. Frey and also Kolliker speak of this reti- 
culum (‘ Manual of Histology,’ partii, p. 451) as being{very 
dense and composed of very delicate fibrils, which are, for 
the most part, non-nucleated, but occasionally, especially 
in young animals, contain nuclei, so that there can be 
little doubt that the reticulum develops into a network of con- 
nective-tissue cells. ‘The meshes of the reticulum contain, 
according to Kolliker, the parenchyma-cells of the spleen in 
such a manner that often only one cell, occasionally two or 
three, occupy one mesh; the reticulum and its cells form 
continuous masses of splenic tissue between the larger blood 
vessels of the pulp, and are themselves penetrated by minute 
vessels. In the spleen of man, in which the minute veins 
form a very dense plexus, Kolliker goes on to say, the tissue 
of the pulp is, therefore, found to form a network of trabe- 
cule (the pulp-trabecule of Frey), and to fill up all the 
spaces of the venous network. According to the same author 
the parenchyma-cells of the splenic pulp represent spheroidal 
uninuclear cells, perfectly similar in appearance to those of 
the Malpighian corpuscles. 
Kyber (Max Schultze’s ‘ Archiv,’ vol. vi, part iv, p. 596) 
describes the matrix of the splenic parenchyma as being com- 
posed of lymphoid cells enclosed in an intervascular network 
of fine fibres, in the nodes of which are found nuclei; they 
are scarce in old, more numerous in young, animals. ‘‘ Besides 
the bright, sharply outlined fibres of this network a second 
network is found in hardened specimens, composed of finely 
granular fibres with notched edges and broad at some points. 
‘This is the intercellular substance of the lymphoid cells.” 
In fresh specimens this intercellular substance appears to. be 
tenacious and finely granular; it becomes more granular 
after the addition of acetic acid; the granules are, however, 
dissolved by the acid after prolonged action. This intercel- 
lular substance forms a part of the parenchyma, and extends 
into the lymphoid tissue of the arteries. 
According to W. Miller (Stricker’s ‘ Manual of Histology,’ 
vol. i, p. 356), the splenic pulp consists of lymphoid cells 
and intercellular substance, the former being for the most 
part small and uni-nuclear, but sometimes larger and multi- 
nuclear cells, which stain more deeply with carmine than 
those of the Malpighian bodies. The intercellular substance, 
2. e. the substance connecting the lymphoid cells, is in the fresh 
condition a pale, transparent, very finely granular, tenacious 
substance, forming a delicate network between the protoplasm 
of the pulp cells. In chromic-acid preparations this appears 
