368 DR. E. KLEIN. 
trabeculze containing slender bundles of muscles, as I did 
not expect to find this according to the assertions of previous 
authors. 
With regard to the structure of the pulp I find that the 
matrix is of quite a different structure from what it is gene- 
rally represented. First of all in well-prepared specimens I 
miss the reticulum of fine fibres mentioned by other ob- 
servers ; in pencilled as well as in unpencilled specimens I 
see a honeycomb of membranes, which only when seen in 
profile have the appearance of fibres. The pulp of the spleen 
of the dog shows this very distinctly (see fig. 1); here I find 
the general matrix represented by a honeycomb of membranes 
which when viewed from the surface possess the appearance 
of a transparent slightly granular film; the septa which are 
in connection with it and which extend in a plane vertical to 
the plane of the preparation give one the impression of 
being highly refractive fibrils (c). The membranes just 
mentioned include numerous nuclei which are chiefly of two 
kinds: (a) large pale round nuclei more or less flattened, and 
(6) smaller elliptical, spherical, or irregular-shaped nuclei; 
these stain much deeper in hematoxylin than the first named. 
In some places the membranous matrix, owing to more or less 
distinct markings, appears as if composed of polygonal, oblong, 
or irregular-shaped territories ; to each territory corresponds 
one of the large pale nuclei; that is to say, in some places the 
membranous matrix appears to be composed of something 
very much like nucleated flattened cells—endothelial cells. 
As has been mentioned before, the membranes form a honey- 
comb ; the spaces (“ cells’’) of this latter (honeycomb) are of 
very different sizes ; at any rate they are merely discontinuities 
in the matrix and are therefore lined by no other tissue than 
the matrix itself; they form a labyrinth of anastomosing spaces. 
Many of them contain coloured blood-corpuscles either single 
or in twos or threes, the larger spaces contain also smaller or 
larger groups of yellowish-coloured lumps (evidently heemo- 
globin-lumps). Here and there a nucleated bud of granular 
substance is seen to project into one or the other of the 
spaces; the bud is in intimate connection with the general 
matrix, both forming a continuity. Most of the smaller nuclei, 
mentioned above as belonging to the matrix, appear to be 
enclosed in such granular buds which are more or less _pro- 
jecting from the general matrix. These small nuclei corre- 
spond, according to all appearances, to the nuclei of the lym- 
phoid or pulp-cells of the authors, and [am therefore inclined 
to think that they (pulp-cells) are in many places only nu- 
cleated buds of the general matrix, which (buds) probably 
