AGf~ICULTURAL RESEARCH, PUSA.

LEISIlMANIAE 451
structures are observed, one large and rounded (macronucleus),
and the other small, deeply staining, and
rod-shaped (blepharoplast). The protoplasm may
bc vacuolated. The organism mUltiplies by binary
fission.
The Leishmania is typically intracellular in the
tissnes, situated in the endothelial cclls of the spleen,
liver, bone marrow and lymphatic glands. It may also
be found in large mononuclear cells ill thc peripheral
blood. One endothelial cell may contain considerable
numbers of organisms.
Cultmes can be obtained from the spleen OIl N.N.N.
medium (vide p. 11\1) incubated at 20 o -24,oc. III
culture the Ol'ganisms increase in size and elongate;
the blepharoplast becomes situated at one end, and
from it a fiacrellllID arises. No undulating membl'ane
develops. 'l1nlH Lcishmawia in culture assumes the
biological characters of a Herpetomon{ts.
Munkeys and dogs can be infected experimcntally.
Transmission of the disease is by insect agency.
The evidence points to the sand-Hy, Phlebotomus
argmltipes as the vector of infection.
DIAGNOSIS
'fhick blood films should be examined as in malaria
diagnosis, but in a large proportion of cases it may
be impossible to demonstrate Leishmania in the
peripheral blood. .
During life the diagnosis may be cstablished by
aspirating fluid from the enlarged spleen by "spleen
puncture." A dry needle should be used. This pro"
cedul'e is not without danger to the patient, and for
this reason liver puncture has been preferred by some
workcrs, though the likelihood of finding the organism
in fluid from the liver is less than ill the case of the
spleen.
It has also been claimed that a diagnosis may be
established by culturing peripheral blood Oil N.N.N.
medium, .