334 
concern to the military because of its 
role as the vector of typhus. The 
research was, therefore, centered 
around this species, and only the more 
effective materials were tested against 
the other two forms with necessary 
adaptations when this seemed desir- 
able. 
In carrying out louse control stud- 
ies, the usual system of testing prom- 
ising materials against natural insect 
infestations was not practical because 
body louse infestations are scarce in 
this country. The entire research 
program was accordingly planned so 
as to develop treatments under labo- 
ratory or simulated practical condi- 
tions. To do this we needed an 
unlimited supply of lice with which 
to test chemicals in the laboratory. 
The final field tests under conditions 
of practical use were undertaken by 
the armed services and by such 
agencies as the Rockefeller Founda- 
tion. 
Because of our method of attack in 
carrying out the research on louse 
control, it is apparent that the mainte- 
nance of a louse colony was among 
the most important aspects of the 
louse program. G. H. Culpepper 
maintained the colony for over 3 
years. As many as 25,000 to 75,000 
lice in all stages of development and 
an even greater number of eggs were 
available at all times. The lice re- 
quired their blood meals at regular 
intervals, and human subjects pro- 
vided these meals, which were offered 
twice each day. We owe much to 
these men who served as subjects, for 
giving a blood meal to as many as 
50,000 lice at one time is not a pleas- 
ant task. Fortunately each subject 
had a rest of about 2 weeks between 
feedings, but the same men served as 
human guinea pigs for other phases 
of the louse work and other projects 
which will be described later. Plate 
1, figure 1, shows the method em- 
ployed in feeding the lice. Between 
2 to 3 percent of the subjects reacted 
so severely that they were unsuitable 
as hosts. In between meals the lice 
ANNUAL REPORT SMITHSONIAN INSTITUTION, 1948 
were held at a temperature of 86° F. 
and at a relative humidity of about 
60 percent. 
Methods for testing various insecti- 
cides as potential louse killers had to 
be developed. R. C. Bushland, G. W. 
Eddy, H. A. Jones, N. B. Carson, who 
were responsible for the laboratory 
phases of the louse project, considered 
and tried various procedures which 
permitted accurate and reliable meth- 
ods of determining if a given material 
was worth testing on lousy individuals. 
The first procedures consisted of a 
simple test in which lice were exposed 
on chemically treated cloth placed in 
asmall beaker. Some 7,500 chemicals 
were tested in this manner. Only a 
few were worth testing by the second 
method, known as the arm-and-leg 
method. The cloths shown on the 
arms and legs of subjects (pl. 1, fig. 2) 
were treated with test chemicals, and 
lice were confined in them for at 
least 1 day. The lice did not suffer 
from lack of nourishment, as any of 
the subjects wearing ineffective treat- 
ments would testify. 
The third step which was carried 
out under the supervision of L. C. 
McAlister and G. H. Culpepper re- 
quired the full cooperation and ex- 
treme patience of our research sub- 
jects. In this test, the subjects lived 
in barracks and were dressed as our 
soldiers would be. They wore part 
woolen winter underwear. Several 
hundred lice and a thousand or more 
eggs from the colony in various stages 
of development were then placed on 
each subject. Promising materials 
were then applied to the underwear 
as a 5-percent powder at the rate of 1 
ounce per garment. 
This was a rigid test and we felt 
certain that any material that would 
free our subjects of lice and keep them 
free of lice which were added at inter- 
vals of several days would be effective 
against natural infestations. ‘The suc- 
cess of the materials in actual practice 
which we recommended to the armed 
services confirmed this belief. 
The outstanding accomplishments 
