I3I 
seen to feed, two on No. XLV, and one on No. XLIV. On arrival at our camp 
they were segregated and carefully kept from all association with other cattle. 
The temperature remained normal until September 3rd, the fifteenth day after 
being bitten. On September 6th, the eighteenth day, trypanosomes were seen in 
the blood of both. This trypanosome was morphologically identical with that we 
have called T. vivax. On September t3th (XLVj and September i6th (XLIV) 
T. iimor-phon appeared, and both organisms were present until September 30th, 
when No. XLV died. Both had been submitted to treatment by Atoxyl and 
Mercury, and No. XLIV has been detailed elsewhere, (vide chart ii.) 
This double infection by such a small number of flies as were seen, 
and on a road where game is scarce, caused further enquiries to be 
made, and we found that a span of oxen had travelled that road on 
August 14th, five days prior to the date our animals passed. On 
September 21st we examined this span, and found two animals 
infected with T. dimorphon, and a third showing both T. dimorfhon 
and T. vivax. 
If the Glossina morstlans which bit Cases Nos. XLIV and XLV 
had not derived these organisms from game, it would appear that 
they have the power of transmitting five days after the infecting feed, 
which would have been taken from this span, whose owner reported 
that he had lost several animals during the months of June to 
September from what he regarded as ‘ fly ’ infection. 
CONCLUSIONS 
1. That trypanosomiasis of domestic stock is very prevalent in 
the Northern area of North-Western Rhodesia, and that it is due to 
T. dimorphon (Dutton and Todd), T. vivax (Ziemann), and one 
morphologically allied to T. brucei (Plimmer and Bradford). 
T. theileri also occurs, but does not appear to cause serious damage. 
2. That these trypanosomes may be transmitted by Glossina 
morstlans, Siomoxys calciirans, and a species of Lyperosia. In 
nature it will depend upon the conditions under which cattle are 
maintained, to which of these genera special attention must be paid 
in prophylaxis. 
3. That treatment, as detailed in a previous report, shows certain 
in iCdtions of success, and we urge facilities for a continuation of the 
wor on this disease, which tends to stagnate the proper development 
of a wealthy mineral and agricultural country. 
