238 TETANUS 
be perfectly conscious to the last. They seem to be possessed of a 
feeling of terror. 
The duration of the disease varies in different species and in different 
individuals of the same species. In the horse it may last for two or 
three days only or it may continue for several weeks. In cattle the 
course is usually less rapid, but it rarely runs longer than two weeks. 
In sheep it usually terminates fatally within a week and often in two 
or three days. 
Morbid anatomy. The gross examination of the tissues at post- 
mortem of animals dead from tetanus is usually negative. It has 
been pointed out by Goldscheider and Flatau that in experimental 
animals there are certain characteristic changes in the motor cells of 
the anterior horns of the spinal cord which in the order of their develop- 
ment depend upon the concentration of the toxin or virulence of the 
bacteria injected and upon the duration of the disease. The changes 
are primarily an enlargement of the nuclei, which at the same time 
become more distinct; then follows an enlargement and disintegration 
of Nissl’s cell-granules with an enlargement of all of the nerve cells. 
These investigators also found that where antitoxin had been used it 
had a distinct retarding influence upon these changes. They found 
like lesions in the spinal cord of a human subject dead of tetanus. 
Very similar results have been obtained by Matthes, Westphal, Goebel 
and others. The lesions point to the anterior horns of the spinal cord 
as the primary seat or origin of the tetanic contractions. The changes 
pointed out above are said by Moschowitz to be characteristic of 
tetanus and constantly present. The motor ganglia cells of the 
anterior horns of the spinal cord seem at present, therefore, to be the 
most likely source of the spasms, due apparently to a specific affinity 
between those cells and the tetanus toxin. It is possible to explain 
also the local spasms on this hypothesis as the toxin elaborated by the 
bacilli acts on the nerves terminating in the affected region. The 
experiments of Tizzoni and Cattani suggest the possibility of such a 
theory. There is, however, need for further investigation on this 
subject. 
A considerable number of lesions may be found elsewhere in the 
body, none of which can be considered as characteristic of the disease, 
but which are secondary to the tonic contractions. The blood, owing 
to lack of oxidation, may be dark colored. There may be numerous 
ecchymoses and sanious exudates in the subserous and mucous mem- 
branes. The lungs may be variously affected according to the extent 
