32 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol 13 
ceeded in demonstrating the causative agent, an organism which he 
considers to belong to a new group of disease agents, that is, it is neither 
bacterial nor protozoan. He has worked out the life history of the 
organism in some detail, and has recently named it. No cure, how¬ 
ever, has yet been discovered. Four medical men have thus far lost 
their lives in this work, three through accidentally acquired infection. 
The most recent death was that of Dr. Arthur McCray, director of 
the State Hygienic Laboratory, during the past summer. 
Entomological workers were early brought into the field by the 
apparent fact that the best hope of controlling the disease lay in the 
control of the tick which transmits it. The work was first taken up by 
Prof. R. A. Cooley, and later by the Federal Bureau of Entomology. 
The life history of the tick, and eradication measures were first worked 
out and actual control was initiated in 1912, the Public Health Service 
also cooperating. 
The area of operation has gradually been extended until it now in¬ 
volves approximately 125,000 acres. The two federal agencies, how¬ 
ever, withdrew in 1917, and since then the work has been carried on 
solely by the Montana State Board of Entomology. That control 
efforts have met with some measure of success is attested by the facts 
that considerable areas have been freed of ticks and, whereas up to 
twenty-five or more cases a season were the rule, during the past two 
years there has been but a single case in the area where the work has 
been conducted. The reduction in cases is attributable in part to the 
control work, in part to education to avoid infection, and perhaps in 
part to little understood natural factors. There is some reason to 
expect a slight increase in the number of cases during the next few 
years, especially in certain areas outside the control districts. 
The work of control, however, is a long and tedious operation, alike 
to those in charge, and to the local farmers and others involved, and 
two questions persistently present themselves. One concerns the 
permanency of the results attained, the other the possibility of finding 
some simpler and quicker method of operation. 
Permanency of results is especially to be desired, but knowledge on 
this point is limited by lack of knowledge of the real source of the 
disease among wild mammals, among which, there seems no reason to 
doubt, lies the real source of the disease. The question cannot, there¬ 
fore, be satisfactorily answered. Questions of the susceptibility, 
immunity, chronic infectivity, habitat, periodical variations in abun¬ 
dance and distribution, and the seasonal migrations and habits of these 
animals are all intimately involved. Even though we may successfully 
eradicate the tick, it is possible that the real condition which is the very 
bed-rock of the trouble may be left behind. For example let us sup- 
