28 
NOTES ON THE COMMON PATHOGENIC 
presenting affinities is difficult unless the original description 
of Dutton and Todd be borne in mind. It is necessary for 
a trypanosome to manifest all these three morphological 
forms before it can be accepted as of this species. The 
following list embraces the species most liable to be confused 
with T. dimorphon : T. congolense, Broden ; T. pecaudi, 
Laveran; T. confusum, Montgomery and Kinghorn (a name 
given to the species maintained at Liverpool and Paris as 
T. dimorphon, the name is pre-occupied by Luke, 1906) ; 
T. montgomerei, Laveran ; T. nanum, Laveran. Of these 
T. pecaudi alone manifests a free flagellum, but it may be 
distinguished from T. dimorphon by the fact that forms similar 
to the ‘ Tadpole ’ are not found. 
Biology. Capable of development in all Laboratory 
animals. Man appears to be insusceptible. Culture in 
vitro has been realised. 
Transmission. The confusion which has occurred with 
this species renders much of the evidence on transmission in 
nature of small value. Trypanosomes of the dimorphon group 
have been transmitted by Gl. palpalis (Boubard and Bouet). 
Bruce, Hammerton, Bateman, and Mackie have shown that 
the form they found in Uganda undergoes cyclical development 
in this fly. 
The writer found a trypanosome in Northern Rhodesia 
which responded in all details to the original description of 
Dutton and Todd. In this locality Gl. palpalis is absent. 
Gl. morsitans exists and is the species locally incriminated. 
From circumstantial evidence, the genus Stomoxys, sp. incert., 
was blamed and subsequent evidence has indicated that this 
or neighbouring species of trypanosomes can be spread in 
localities where Glossinae have not been found. It is interesting 
to note that no tsetse flies have been found in the locality of 
Mambrui from whence my preparation comes. This very 
important question is still sub judice, but we have knowledge 
that the genus Stomoxys can spread Trypanosomiasis. Martin, 
Leboeuf, and Roubard have succeeded in transmitting T. brucei 
by means of S. calcitrans and S. glauca. 
Since the year 1902 the island of Mauritius has suffered 
severely from the ravages of Surra ( T . evansi), which was 
