206 
Bilharziosis in South Africa 
The Parasites. 
I do not intend to enter into the anatomical description of the actual 
parasites or to give an account of the dimensions or other minute 
details of their ova. That is a matter to my mind requiring the 
knowledge of an expert helminthologist. 
The natives of South Africa are infected then with the two forms of 
the disease, viz. the classic form and Manson’s Bilharziosis. 
I have found both terminal and lateral spined ova at autopsies and 
when examining the excreta from patients in hospital, and I believe the 
parasites which deposit these two distinct forms of ova normally infest 
different organs, though the terminal spined ova occasionally trespass 
on the preserves of the lateral spined one. 
I have been able to find the worms most readily in the portal veins 
of the liver (see Table II), but the parasites in that situation are, 
I understand from Dr Leiper (London School of Tropical Medicine), to 
whom specimens were submitted, of the male sex and immature. To 
find the mature worms it is necessary to examine the ramifications of 
the venous system of the bladder and rectum. I have never found 
worms or ova in the arterial system. 
Some of the ova probably remain in a calcified state long after the 
worms have disappeared from the system. That there may be two 
separate trematodes is, I think, supported by the fact that the terminal 
spined ova is the only variety ever found by me in the urine or mucous 
membrane of the bladder and ureters 1 . 
In the faeces and mucous membrane of the large intestine lateral 
spined ova are generally found, with sometimes, however, a few terminal 
spined ones amongst them, and these latter are frequently in a calcified 
state, suggesting that they have worked their way from the bladder 
tissues rather than that they have been deposited by the blood stream. 
On four occasions at autopsy(examinations on two Angonis,one Shangaan, 
and one Quilimane native) I found lateral spined ova in the mucous 
membrane of the large intestine, but although I carefully scraped and 
examined every portion of the mucous membrane of the bladders, no 
ova of any kind could be found in these organs. 
My observations of the occurrence of the lateral spined ova are 
1 In a discussion reported in the Lancet of April 20th, 1889, Dr Moon stated that “ he 
had found both terminal and lateral spined ova in both bladder and rectum.” This 
statement does not hold good in South Africa. 
