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gradually becomes narrower towards the end where it is covered with long hairs. In the male
the penis is seen flexed in a notch between the seventh and eighth segments.
This bug is distributed throughout Europe and North America, and is also found in Suez,
Egypt, the Sudan, the North-West Frontier Province of India, China, South Africa and
Australia.
Cimex rotundatus Sign or the Indian bed-bug is darker than the above species being of
deep mahogany colour ; its head is not as long or as broad as that of lectularius. Its prothorax
is also narrower and shorter, is more rounded and not flattened at the sides as is the prothorax
of the type species. Its abdomen is less orbicular, being broadest at the second segment and
tapers more abruptly towards the end ; in all other respects it is similar to Cimex lectularius.
Cimex rotundatus is distributed throughout India, Burma, Assam, Malay, and is also found
in Aden, Sierra Leone, the Islands of Mauritius, Reunion, St. Vincent and Porto Rico.
Cimex pipistrelli Jenyns is similar in colour to rotundatus, its prothorax is also less marginal
and in all other respects it is more closely allied to the Indian bed-bug.
Cimex columbarius Jenyns has a similar prothorax to lectularius and is also of the same colour.
Dissection of the bed-bug. The following method of dissecting the bed-bug has been found
satisfactory. After having killed the insect by placing it in a tube with a plug of cotton wool
containing a few drops of chloroform, it is taken up with a fine pair of forceps and the legs are
pulled off. In removing the fore legs it is necessary to be careful not to injure the prothorax,
as they are firmly fixed in concavities on its under surface. The elytra are next removed by
raising them with a fine pair of forceps and gently twisting them off from their joints at the
angles of the mesothorax. The bug is now placed in a drop of normal saline solution with its
head directed towards the dissector. A fine needle is inserted with the left hand into the right
side of the prothorax, while with another fine needle in the right hand the joint between the
prothorax and mesothorax is separated. By gently drawing the needle in the left hand and by
exerting pressure on the dorsal surface of the abdomen with the other needle, the œsophagus,
midgut and the remaining part of the intestinal tract are drawn out, and any portion can then
be isolated and examined. The salivary glands lying on each side of the œsophagus are also
exposed by this method. The ducts of the salivary glands and the oesophagus can be followed
into the crop situated in the head. by carefully removing the prothorax.
Conclusions.
1. Though Kala Azar is a chronic disease lasting many months and often years, it
occasionally runs an acute course terminating in form four to five months as illustrated by the
case described above. In these acute cases as well as in the chronic ones terminating with
ulceration of the large intestine, the parasites are found a few days before death in large.
numbers in the peripheral blood in the leucocytes and endothelial cells, and the latter are
probably the source of all the parasites seen in the circulating blood.
2. Though the parasites are most abundant in the peripheral blood towards the end of the
disease, they are also found in the early stages as a case recently seen clearly illustrated.
3. In the female as well as in the male bed-bug (Cimex rotundatus) the parasites have by
the third day passed through all the intermediate stages of development described above up to
the formation of the mature flagellates. Rapid multiplication by rosette formation is a charac-
teristic feature of the development of the parasite in the bed-bug. As the male bug sucks blood
it probably plays as important a rôle in the transmission of the disease as the female bug.
4. The infection acquired by the bug varies considerably, some ingesting large numbers of
parasites, others only a few ; and there is no evidence at present to show that the development
in the bug depends on variations in the temperature.
5. The tendency that the disease has to linger in a house for a long time is probably
explained by the fact that the parasite may remain in the midgut of the bug for several days
before beginning to develop, and, as the nymphs which take from seven to ten weeks to arrive
at maturity, may ingest the parasites shortly after hatching, and as a rule feed only once
between each moult, the infection may remain for a considerable time in a house; there is no
evidence at present to support the view that the infection is inherited by the bug.
I wish to take this opportunity of thanking Mr. Lounsbury for specimens of Cimex
l e c t u l a r i u s
L . f r o m S o u t h A f r i c a , M r . W . R a i n b o w , A u s t r a l i a n M u s e u m f o r s p e c i m e n s o f
C i m e x
lectularius from Sydney, Dr. C. W. Branch for a large collection of Cimex rotundatus Sign. from
the Island of St. Vincent, Dr. J. W. W. Stephens for specimens of Cimex rotundatus from
Sierra Leone, Dr. C. A. Butler, United States Naval Hospital, San Juan, for specimens of Cimex
rotundatus, and Mr. W. L. Distant for information and advice.
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