222 
DR. E. KLEIN ON THE SMALLPOX OE SHEEP. 
vacdnce ; this Micrococcus, as well as any other Micrococcus, i. e. Sjphcer obacterium, 
differs completely from Hallier’s Micrococcus, as the former stand in no genetical rela- 
tion whatever either to other kinds of Bacteria or to the spores of other fungi with a 
mycelium. 
I come now to describe the results of my own observations of the lymph of variola of 
sheep. Clear lymph, which had been kept for several days in a sealed capillary tube, 
was diluted with thoroughly boiled half per cent, saline solution and was used thus : 
one portion of the diluted liquid having been reserved for further experiments, the 
remainder, which was intended for microscopical examination, was sealed, immediately 
after it was prepared, with dammar varnish and examined. It contained structures as 
represented in Plate 29. fig. 1. First there were to be found minute highly refractive 
spheres isolated, or in couples or in small groups ; they correspond to the solid granules 
(Micrococci) in Cohn’s figure in the above-mentioned paper. They did not show any 
other than Brownian movement. Then there were present a great number of circular 
pale bodies, which, from their circular shape and size, could be easily recognized as decolo- 
rized blood-corpuscles. They were generally to be met with in small groups, between 
the members of which the same spheres, i. e. dark granules as before mentioned, were 
seen in couples or in necklace-like chains; these Micrococci followed exactly the inter- 
stices between the blood-corpuscles. Besides these structures there were to be seen a 
few rod-like Bacteria belonging to those types which are designated by Cohn as Bacte- 
rium termo and Bacillus subtilis. 
They were either isolated or in couples, and exhibited only slight oscillatory move- 
ment. The most characteristic features, however, were the following : — 
(a) Lumps of a pale transparent substance containing very irregularly distributed 
smaller and larger granules, the smaller granules being pale and indefinite, the larger 
ones very bright and highly refractive. 
" (b) Spheres generally considerably larger than the spheres above mentioned, at least 
twice as large. They were arranged in small groups, chiefly composed of couples or of 
necklace-like chains. 
These spheres were different from the above-mentioned ones, not only in their being 
larger, but chiefly by the fact that they were bordered by a sharp line as if by a mem- 
brane, whereas their contents appeared perfectly transparent. They correspond to the 
spheres figured by Sanderson, and to the spheres (transparent) in Cohn’s figure, only 
that they are generally larger than the dark solid granules, and not of equal size as 
represented in Cohn’s figure. 
(c) Groups consisting of the highly refractive small spheres above named and the 
granules mentioned under (a). They are also represented in Cohn’s figure in Virchow’s 
4 Archiv,’ with the difference that the transparent spheres are always larger than the 
solid highly refractive ones. On careful examination of these groups of mixed spheres, 
it is found that there are all transitional forms between the two kinds of spheres which 
