1888 - 89 .] Dr R. W. Felkin on Tropical Diseases. 
291 
the body of a trasmatoid hsematozoon, which is found in the portal 
system, the mesentery, bladder, &c. It produces hsematuria and 
anaemia more or less profound. 
Geographical Distribution . — The distoma has, so far as we know, 
a peculiar and very limited area of distribution. It is found in 
Mauritius, where the disease it causes was first described in 1812 
by Chanotin. It is strictly limited to the delta of the Nile and to 
various points of the White Nile between 6° N. and the Albert 
Nyanza. It is also indigenous at the Cape, where it is strictly 
confined to the coast territory and to the banks of streams for a 
distance of some 10 or 20 miles from the sea. Its chief seat 
is in the south-eastern districts of Cape Colony near Algoa Bay, 
especially at Uitenhage and Port Elizabeth, the neighbourhood of 
King William’s town and East London in Kaffraria, as well as at 
several places in Natal; for example, on the banks of the Umlasi, the 
Ungeni between port Natal and Pietermaritzburg, and the Umhloti. 
It is probably also found in various other places in Central Africa. 
Remarks . — A knowledge of the geographical distribution of this 
parasite is of great importance, because, by taking proper precautions 
when residing in its limited area of production, it is possible to 
escape its ravages. There can be no doubt that it exists in stagnant 
pools, in the shallow water of declining rivers, near estuaries, and 
at the sea coast. It is affected by season, being found in the water 
in the summer, and it is during the summer too that most people 
are affected by the disease. It is curious to notice its preference 
for the male sex, and it is most commonly seen in them between 
the ages of five and thirty-five years. At Pietermaritzburg the 
majority of youths are affected by the parasite. As it can 
only obtain entrance into the body by means of drinking water 
or in bathing, the necessary precautions should be taken, and 
Europeans who may contract the disease should immediately 
remove from the infected area. 
VII. Beri-Beri. 
(See Plate V. A.) 
Synon. — Barbiers; Loempoe (Java); Kak-ke (Japan); Maladie 
des Sucreries (French Antilles); Sleeping Sickness (west coast of 
Africa) ; the Bad Sickness of Ceylon. 
