REVIEW—TROPICAL MEDICINE, ETC. 97 . Rs It is due to the protozoal parasite of kala-azar, which may be found in the liver and other organs after eath.

‘ 4, This form of cirrhosis of the liver is much commoner in Lower Bengal than a true malarial cirrhosis, with which it has probably hitherto been confused. It is, however, much less common than atrophic cirrhosis due to unknown causes.

Patton,! who has done the work on the development of the parasite in the bed-bug, records his latest work from which we cull a few notes and his conclusions. The large endothelial cells mentioned above, which contain the parasites in large numbers and are found in the liver, spleen, bone-marrow and lymphatic glands, occur in the peripheral blood of patients some days before death. ‘‘It seems most probable,” says Patton, ‘‘ that the rupture of these cells and the liberation of the parasites they contain, explains the occurrence of the large numbers of parasites in the peripheral blood of patients suffering from ulceration of the large intestine. Once the parasites are set free in the plasma they are immediately taken up by mononuclear, eosinophyl or polymorphonuclear cells.”

It is suggested that the brawny swellings met with in the course of the disease, and cancrum oris, which is so common, both owe their origin to hemorrhage caused by the blocking of a small vessel by one or more of these large cells.

Attention is drawn to large, non-nucleated, parasite-containing, blue-staining (with Giemsa) bodies, also found in the peripheral blood. Some believe them to be altered red blood corpuscles, others, detached buds of macrophages or mononuclear cells.

The general evidence seems to be against the occurrence of parasites in the red cells.

In continuation of his last report,? Patton gives more confirmation regarding the development of the parasites in CO. rotundatus. After the early stages of development, 7.e. increase in volume of protoplasm and in size of micronuclei which show signs of commencing division, one or other of two things takes place: (1) the parasite may rapidly pass on to flagellation; or (2), what is more important, they further enlarge and by consecutive division of the macro- and micronuclei produce a rosette of from four to eight parasites. “The single flagellates enlarge and begin to divide longitudinally to result in oval or spindle-shaped cells, while the rosettes, after flagellation, begin to divide up into separate, elongated flagellates. The oval or spindle-shaped parasites divide repeatedly . . . . and result in smaller and more irregular forms. All these changes may be seen in the bug during the first three days. Still later, longitudinally division of the oval and irregular flagellates progresses rapidly, so that by the fifth day the majority have become small or spirilla-like flagellates.”

Patton also deals with temperature requirements and concludes that the disease usually begins in the cold weather, but this is not to say that infection can only take place during this season The final stages of development and the method of re-entry into the human body have not yet been determined, but the conclusions 6n this very valuable work so far are as follow :— 1. Though kala-azar is a chronic disease lasting many months and often years, it occasionally runs an acute course terminating in from 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.

8. 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 “characteristic feature of the development of the parasite in the bed-bug.” As the male bug sucks blood, it probably plays as important a réle 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.

Ae Patton, W. 8. (1907), “The Development of the Leishman-Donovan Parasite in Cimex Rotundatus.” Scientific Memoirs of the Government of India, No. 31.

* Patton, W. S. (1907), “Preliminary Report on the Development of the Leishman-Donovan Body in the Bed-Bug.” Scientific Memoirs of the Government of India, No. 27.

Leishmaniosis— continued