8
which pass into a large flagellar vacuole just anterior to the micronucleus. The macronucleus
of the smaller cell is also situated at the posterior pole and its micronucleus lies close up to it.
Its flagellum is almost separated from that of the parent cell being attached by its end alone.
The commencing division of the flagellum and macronucleus of the parent cell and the position
of its micronucleus show that it is about to divide longitudinally.
On January 2nd the remaining bugs, three adult males and one female, wore dissected
between 12 noon and 1-30 P.M., the midguts being dissected out and prepared as described
above ; in addition smears were made from the crops and salivary glands of all the bugs. In
two films, one prepared from the midgut of a male and the other from that of a female, there
were a number of parasites, some exhibiting the earliest changes towards development, others
more advanced, as well as a few rosettes and small flagellates.
Plate II, fig. 5 e and f, shows two parasites in the early stages of development ; in the smaller
the flagellar vacuole is seen. as a small pink area lying near the micronucleus. The larger parasite
measures 8μ in length and 4 . 5μ in breadth, one end being rounded and the other pointed ; its
protoplasm stained dark blue with Giemsa's stain and contained some small pale areas, but none
of the distinct vacuoles usually seen at this stage. Its micronucleus a little enlarged lay close
to the macronucleus which is round and compact staining deep red.
Plate II, fig. 6 a, shows another cell of a similar nature, though it is almost round ; its
protoplasm is less deeply stained and contains a few indistinct vacuoles. Its macronucleus
lying near one end is almost divided into two, while the micronucleus is situated about the
centre and lying near it is a faint pink mass suggesting the early development of a flagellum,
These parasites clearly show that the Leishman-Donovan body may remain in the midgut of the
bug for at least five days before they begin to develop.
The rosettes seen in these slides are similar to those described above, the majority consisting
of fully developed flagellates. Plate II , fig. 5 c, shows a long flagellate which measures 9 .5μ in
length and 2.5μ in breadth ; its oval macronucleus is situated about the centre of its body and
lying close to it and about 1 . 5μ from the anterior end is the micronucleus. The posterior end of
the parasite is pointed and situated about 3 μ from this end there are two small pink masses which
on higher magnification are seen to consist of a number of chromatic granules. This is the first
parasite that has shown this appearance, though in another long flagellate (Plate II, fig. 4) there
was a suggestion of the same structure. From these isolated specimens it is impossible to say
what this represents, but further reference will be made to it later.
Plate II, fig. 5 d, represents two attenuated flagellates attached by their poles, and from
the outer side of one of the cells a spirilla-like parasite is seen splitting off. The macronuclei of
the two parasites are circular and compact staining uniformally dark red or almost black with
Giemsa's stain ; in one cell the macronucleus is near the anterior end and in the other towards
the posterior pole, and in each case the micronuclei are lying close up to their respective
macronuclei. The protoplasm of these cells stains dark throughout and is devoid of granules or
vacuoles. The spirilla-like parasite is 5 . 4μ in length and l μ in breadth, and in its protoplasm
there are two small chromatic granules, the anterior being distinctly rod shaped.
These pairs of attenuated. flagellates are seen in all stages of longitudinal division ; some
are without flagella and are similar to those described and figured in my first report which
therefore represent a very late stage in the development of the parasite. Plate II, fig. 6c,
represents one of these attenuated flagellates lying free; it measures 9 μ in length and 1.2μ in
breadth, and its flagellum measures 10 μ . The macronucleus, which consists of a number of
chromatic rods, is situated about the centre, while the micronucleus is 2 μ from the anterior end.
The protoplasm of the cell appears very granular and stains deep blue with Giemsa's stain.
The flagellum, a stout filament, is inserted into the body near the micronucleus, though not
attached to it.
Another type of small flagellate dividing longitudinally is shown in Plate II, fig. 6 b. Its
two daughter cells further show evidences of multiple division of their macro-and micronuclei.
In one of these there are two macronuclei, one circular in shape situated at the posterior pole,
the other having a dumb-bell appearance situated about the centre. There are also three
micronuclei in this cell, two near the central macronucleus and the other towards the posterior
end. In the second cell there is a single macronucleus lying about the centre with the
micronucleus near it. Two flagella are seen passing out from one cell and one from the other.
Fig. 6 d shows two flagellates in each of which there are two macronuclei, two micronuclei and
a single flagellum.
The process of irregular division in the larger oval forms undoubtedly results in the
formation of small irregularly shaped flagellates shown in Plate II, fig. 6 e and f ; one of these
small cells shows a dumb bell shaped macronucleus and three micronuclei. Its posterior end
is distinctly pointed while the rest of the cell is rounded. Fig. 6 f represents two small
flagellates attached by their posterior poles in which the round macronuclei are lying with the
two micronuclei near them. The protoplasm of all these small cells stains uniformly dark blue
with Giemsa's stains and contains neither vacuoles nor granules.
Plate II, fig. 6 g, shows a large flagellate measuring 15 μ in length ; two macronuclei are
seen lying on each side of the centre of its body and a little posterior to one there is a single