DR. E. KLEIN ON THE SMALLPOX OE SHEEP. 
233 
not impossible that they do not belong to the tissue of the skin itself, but that they 
perhaps correspond to what Hallier calls Cryptococcus. This is also supported, to a 
certain extent, by the fact that I found them chiefly in those parts of the subcutaneous 
tissue which (as I could make out from several circumstances) had been penetrated by 
the canula of the injecting-syringe when the inoculation with lymph was performed. 
The most important characteristics of this stage of the disease, however, are those 
which depend on the changes in the lymphatic vessels in the deeper part of the corium. 
The lymphatic vessels (those accompanying blood-vessels and filled more or less with 
lymph-corpuscles, as well as the others) are, as stated above, distended, and from this 
reason, as well as from the lymph-canalicular system being also distended, are distinctly 
seen to be in direct continuity with the latter, viz. with the interfascicular lymph- 
canalicular system. 
Many of these lymphatics contain a material which, as represented in Plate 31. figs. 9, 
7, & 8, is composed of a transparent matrix, in which lie imbedded highly refractive 
spheres, in some parts closer than in others. 
From the lymphatics this material extends also into the interfascicular lymph-canali- 
cular system, or, more correctly speaking, it extends from the latter into the former. 
In some lymphatics these highly refractive granules are seen to be arranged in shorter 
or longer, branched or unbranched filaments. These filaments are more or less curved, 
and resemble either necklaces or smooth filaments according as the individual joints 
are more like spheres or like rods. One and the same filament may also be partly 
granular, i. e. like a necklace, and partly smooth. 
In those places where they are to be found in greater numbers they are seen to cross 
each other and decussate, so as to form a close feltwork. 
These relations come out very distinctly in a little later stage. Thus in a pock cut 
out a little after forty-eight hours (see Plate 31. fig. 9), it is seen that in the lymphatics 
of the deeper stratum of the corium the granular mass is not only replaced by filaments 
(or, let us say at once, that most of the granules have arranged themselves into filaments), 
but, what is also of great importance, the filaments have more or less lost their granular 
aspect, and have become smooth, longer, and more branched. 
In fig. 10, 1., a lymphatic vessel of the subcutaneous tissue is shown, in which is seen 
a network of branched filaments without granular matter, some of which exhibit small 
swellings at one or other point of their course, while in other instances the swelling is 
at the end of the filaments. 
There can, I think, be no doubt whatever that the granular material is not plasma 
or serum coagulated by the hardening reagent ; for these granules are not only of a 
definite large size (very much larger than the granules one meets with in coagulated 
serum), but stand, as the examination proves, in a definite genetical relation to the 
filaments. As regards these latter there is only one possible explanation, viz. that they 
represent an organism. 
In pocks which were cut out between twenty-four and eighty-four hours, all the 
