Gr. H. F. Nuttall 
51 
Algeria, suggested that lice, with a high degree of probability, would 
prove to be the vectors of typhus. 
Nicolle, Comte and Conseil (9. ix. 1909, pp. 486-489) observed that 
typhus in Tunis occurred amongst the poorest classes living under 
unhygienic conditions, and, on the evidence afforded by the epidemiology 
of the disease, they undertook experiments with lice. On the date 
mentioned, they reported that they had successfully transmitted typhus 
from monkey to monkey by means of the bites of infected lice ( corporis) 
that had fed on a typhus patient 1-7 days previously. 
Ricketts and Wilder (16. iv. 1910, pp. 1304-1307) confirmed the 
observations of the French authors, finding that lice 1 , fed either on 
man or monkeys suffering from typhus, were capable of infecting 
monkeys by their bites. The American authors also infected monkeys 
through the scarified skin by means 'of the gut contents of lice killed 
three days after they had fed upon a typhus monkey. 
Wilder (19. vn. 1911, pp. 72, 73, 89, 92-98) next reported upon the 
successful infection of seven out of ten monkeys that were bitten by 
lice ( corporis) p^yiously fed on typhus patients, also on an experiment 
with two monkeys that were infected through the contents of such 
lice placed upon the scarified skin. The virus was conveyed from one 
monkey to another by lice, and still another monkey was infected by 
subcutaneous inoculation with the intestines of six lice. The minimum 
number of lice required to infect a monkey by their bites in these experi¬ 
ments was reckoned at 17. The statement is made, on the basis of 
one experiment only, that the virus of typhus is probably transmitted 
hereditarily in the louse. Transmission experiments by means of fleas 
and bugs gave negative results. The author suggests prophylactic 
measures being taken against lice (corporis). 
Goldberger (1. hi. 1912, pp. 298-307) conducted experiments with 
the New York strain of typhus. He fed corporis on a typhus monkey 
and afterwards on two healthy monkeys, one of which ajjparently 
reacted. Two experiments upon transmission by means of crushed 
lice, made from monkey to monkey, failed, but two similar experiments 
made from man to monkey succeeded apparently for these monkeys 
failed to react to a subsequent inoculation with 3 c.c. of virulent typhus 
blood. Head-lice (capitis), fed upon a typhus patient, were crushed 
and inoculated into a monkey with positive result, and two out of three 
monkeys were infected successfully through the bites of such lice 2 . 
1 Called throughout the paper “P. ve-stamenti” (sic). 
2 These are apparently the only experiments made with capitis. 
