214 
Experiments 41 and 4 2. —Rats. On November jo, 1903, these two ami; 
were inoculated subcutaneously with the fluid obtained by rubbing up 16 lam* 
freshly-caught at Wathen, in normal saline. Roth rats were examined freqim 
(every three days) until April, 1904; neither ever became infected. 
It is noteworthy that no trypanosomes were seen in the blood 
from the alimentary canals of six freshly-caught larvae, although 
living trypanosomes have been found in the intestines of larvae upio 
10 to 13 hours after they had fed on a known infected animal 
(b) To ascertain whether larvae, caught in native huh at With: 
and Leopoldville, are able to infect a susceptible animal with trypamm 
by their bites. 
The larvae experimented with were always left in tins containing 
dry sand. Animals, on which it was desired that the larvae should 
feed, were tied to an arched, wire frame-work and placed in the tin; 
so that their cleanly-shaved abdomens rested on the surface of the 
sand. Under these conditions, the larvae commenced to feed in about 
an hour. They apparently fed daily and for many minutes at a time, 
unless the animals were moved, when they immediately burrowed 
into the sand. 
22a larva p f 1 ~C' u i nea -pig. From December 18, 1903, to March 12,19° 
intervals nnfa nt 6 . blood Was examined frequently until May, 1904, and then 
were never seen ° Vember ’ I9 ° s » when the animal died of pneumonia ; trypanosonn 
II. INTERRUPTED FEEDING 
Lo ascertain whether larvae immediately previously fed o 
ima heavily infected with Trypanosoma gambiense were ca 
ismittmg the parasite by their bites to a susceptible animal. 
xperiments 107a and 108 an infected guinea-pig was pi 
mh .L? C ° r f tW ° llOUrS 111 tJie t,n containing the larvae; it was 
nip-hf ^ \\n aCe< ^ ^ a healthy animal which was left in the tin c 
, ien the infected animals were removed a dozen mag 
hirrhh reqi ‘ einly seen to he feeding on them ; it therefore se 
animal ^ ^ that many of these resumed their feed on the sec 
which fp>r? 1 1C recorc ^ s these experiments the number of lai 
c uring the night on either or both of the animals is no 
Experiment io 7 ci p..? 
both animals. Rlood nea ' pig ‘ On March n, 1904, 39 larvae fed on on> 
October, i 9 o 4) when th - examin ed regularly until May, and then at intervals 0 
somes were never seen * guInea ‘P*& was used for another experiment; trvpa 
