AGf~ICULTURAL RESEARCH, PUSA.

SPIROCIIAETE8
and nan be detected in hlood films. )VlWll defelYCSCencc
OCCUl's it disappears from the blood, but Illay still be
prescnt ill considerable numher:> in the spleen, where
it is phagocytosed by large lllOllolluclear cells.
It is transmitted from person to person by the body
louse, the Pediculus corporis. After this insect has
sucked blood from an infected individual the organ·
isms are demonstrable in the stomach for a day, anci
then disappear. They reappeal' aftcr ahout six days in
the LOlly mi.vity and become 'widespread throughout the
body of the insect. Infection results either through
the contamination of the bite wound with the infective
excreta of the louse, or by the crushing of the infective
lice with the fingers in the act of scratching, and by
the simultaneous inoculation of' the abrasions.
Animal Inoclllation.-Monkeys, white mice and
white rats can be infected experimentally hy subcutaneous
iujcetion of blood from a case of relapsing
1'evcr.
BORRELIA (or SPIRON"EMA) DUTTONI
The organism of West African relapsing fever
(African Tick Fever).
This organism is morphologically and biologically
similar to Burr. obcrmeieJ'i, but pl'ohably represents a
separate variety 01' species. Its distribution ill the
disease is also similar, hnt it is transmitted by a tiek
(OruitllOdol'U8 'nwilbaia). Infection probably results
from the eontamiuation of the hite-wound by the
infective excreta of the insect. It has been suggestc(l
that in the tiek the urganism goes thl'ongh somc stnge
in a life-cycle. "Chromatin" grallllies have also been
observed in the spirochaete; these are extrudell, Hnd
have becn l'egm'ded as a phase in the: life-}listory of
the organism. l j
hese granules ha vo becn noted in
the Malpighian tubules of infee:tive ticks. Infectivity
may he transmitted to the second generation from the
femalc insect,
Barr. duttoni is pathogenic to monkeys and various