502 
Journal of Agricultural Research voi. xxvi, no. xo 
horse 128 is significant in that this is one of the important indications of 
alteration in the central nervous system. 
COMPLEMENT-FIXATION TEST 
The spinal fluids of horse 128 and blackleg calves 1, 2, and 3 were 
subjected to the complement-fixation test for dourine. The spinal 
fluids were not inactivated. Fluid from horse 128 gave a 4+ reaction 
in a quantity as low as 0.05 cc., 0.2 cc. in the control tube showing no 
inhibition of hemolysis. Fluids from blackleg calves 1, 2, and 3 gave 
negative results to the test. Data of the tests are given in Table II. 
It is of interest to note that the spinal fluid of horse 128 gave a 4 + 
reaction with 0.05 cc., while the serum of this animal tested at the same 
time against the same antigen and hemolytic system gave only a 34- 
reaction with 0.2 cc. 
Table II— Complement-Fixation Tests of Spinal Fluids 
a — “Complete hemolysis. d 3+= 75% fixation of complement. 
& 1+= 25% fixation of complement. e 4+— 100% fixation of complement. 
c 2+=* 50% fixation of complement. 
MICROSCOPIC FINDINGS 
The microscopic examination of tissues from this case is intended 
merely to supplement the spinal fluid studies. No attempt has been 
made to study the changes in the peripheral nerves, the larger nerve 
trunks, the sympathetic system, or the spinal ganglia. The spinal cord 
alone was used. Sections were made from the dorsal and lumbar regions 
of the cord, the principal changes described herein being found in those 
from the lumbar region. 
It was first necessary to ascertain if any changes could be seen by the 
ordinary routine method of staining with hematoxylin and eosin. This 
was followed by the more specialized stain, Pal’s modification of the 
Weigert method, and lastly by Heller’s myelin-sheath stain, which by 
virtue of the osmic acid is more sensitive to degenerative changes than 
the universally used Weigert method or its modifications. 
The microscopic changes were not so pronounced as might have been 
expected from the long duration and chronic character of the case. 
The dura mater was thicker than usual, but no excessive hypertrophy 
could be seen in the fibrous tissue or in the number of fixed connective- 
tissue cells. The fibrous bundles were apparently somewhat thicker 
than normal. There was a slight thickening of the walls of the blood 
vessels, which were well filled but not overdistended. No hemorrhages 
