534 
Journal of Agricultural Research 
Vol. XIV, No. 1a 
disease, whether from man to man or whether the parasite passes a stage 
of its life cycle somewhere in nature and is introduced into the body from 
this point. Ophuls (5) and MacNeal and Taylor (4) have expressed the 
suspicion that the disease is an affection of animals and that through 
association with such as are diseased man may become infected. In 
view of the writer's positive findings in cattle, these suppositions are well 
founded. 
Practically all the human cases reported have terminated fatally— 
Wolbach (14) reports a case of recovery—the duration of the disease 
varying from about three months to nine years. The patients manifest 
a variety of clinical symptoms which depend upon the organs involved 
and the extent of the lesions. As the disease progresses from the primary 
center and becomes generalized, practically all the organs may become 
the seat of miliary and larger nodules and abscesses, the symptoms 
corresponding to the location and severity of the lesions. Infection of 
the bones with purulent osteomyelitis, arthritis, and with compression 
of the cord and brain is not uncommon. Remittent fever and night 
sweats appear to be quite constant symptoms, particularly in the later 
stages of the disease. 
DISCOVERY OF THE DISEASE IN CATTLE AND DESCRIPTION OF THE 
PARASITE 
The present writer encountered the infection in bovine bronchial and 
mediastinal lymph glands forwarded from an abattoir in San Diego, Cal., 
by Dr. W. M. MacKellar, of Bureau of Animal Industry. The parasite 
observed in pus from the glands appears to be identical with that found 
in the lesions of human cases (PI. 59, A). In the purulent center of the 
lesion and in the surrounding granulation tissue the parasite is present in 
considerable numbers. It appears as a spherical body varying from 3 to 
35 jjl in diameter and having a doubly contoured and highly refractive cov¬ 
ering, which is from 1 to 5 p thick. In some parasites the protoplasm 
appears very finely granular, while in others it is more coarsely granular 
and sometimes vacuolated. Large spheres containing many smaller ones 
of a diameter about 3 to 5 jjl are observed, and occasionally one sees these 
large bodies in a ruptured state releasing the inclosed spores. The broken 
empty shells may be seen being invaded by leucocytes. Neither mycelia 
nor gemmation forms are ever found in the lesions, although the latter 
type is often simulated when two bodies lie in close contact with each 
other. 
LITE CYCLE OF PARASITE 
The process of forming mycelia from the spherical bodies was studied 
by following the method described by MacNeal and Taylor (4). Fresh 
pus containing spheres was seeded in beef-broth-agar hanging-block prep¬ 
arations and incubated for various lengths of time. After several hours' 
