the seasonal and geographical distribution of the disease and the 
insect, in particular, seemed significant, high temperature apparently 
being inimical to each. At last in 1909 Nicolle, Comte and Conseil 
succeeded in transmitting typhus fever to monkeys by the bite of the 
body-louse. This result was confirmed in the next year in this 
country by Ricketts and Wilder; and Goldberger and Anderson 
showed that not only the body louse (Pediculus vestimenti) but also 
the head louse ( Pediculus capitis) may transmit the specific infection. 
As an illustration of the danger to which those who work on the 
insect-borne diseases are exposed, it may be noted that one of this 
sroup of devoted experimenters, Howard T. Ricketts, contracted the 
disease in the course of his investigations and died, almost at the 
outset of a brilliantly promising career. 
With the outbreak of the European War in 1914, typhus again 
came into public notice as it broke out in malignant form on the 
eastern battle-front. Its effects upon the course of campaigns in the 
Balkans is said to have been very material; but the French, German 
and Russian armies have been protected against its ravages by 
elaborate provisions for the destruction of lice by the disinfection of 
clothing and the cleansing and disinfection of the person, particularly 
of the hair. 
The body louse usually conceals itself in the folds of the clothing, 
depositing its eggs along the seams and wrinkles. A female may de- 
posit nearly 300 eggs which hatch in 3-4 days and reach maturity in 
15-18 days. According to recent studies reported in English medical 
journals,” lice are able to live without food for 2-6 days. They become 
rigid with cold at 10° F. and are killed in 2-6 hours at 104° F. 
Among the various substances which have been employed for the 
destruction of lice, the most efficient appear to be a killing powder 
composed of 96 per cent. naphthalene, 2 per cent. creosote, and 2 
per cent. iodoform, and an ointment known as vermijelli. The 
soldier’s clothing and equipment may be freed from lice by treatment 
in either dry or moist heat sterilizers or in special sterilizers which 
make use of the simultaneous effect of heat and formaldehyde 
in vacuo. Ironing the seams of garments with a hot iron is a simple 
and generally effective method. Military encampments are usually 
provided with special stations for ““delousing”’ or “‘depediculization, ” 
An excellent review of recent contributions to the biology of the louse is to be 
found in ‘‘Household and Camp Insects’’ by E. P. Felt, Bull. No. 194, New York State 
Museum. 
62 
ee . 
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