300 
to  ‘  clean  ’  areas.  Within  the  infected  areas,  it  is  the  most  practical 
method  of  isolating  infected  natives.  The  conditions  present  in  the 
particular  country  concerned  may  possibly  affect  the  results  obtained, 
but  if  it  is  seriously  and  efficiently  applied,  we  consider  that  the  results 
will  more  than  justify  the  cost. 
VII.  OCCURRENCE  OF  CASES 
The  Principal  Medical  Officer,  Dr.  Spillane,  in  a  tour  made  during 
October  and  November,  1907,  found  twenty-six  cases  of  the  disease 
in  North-Eastern  Rhodesia,  two  in  villages  on  the  Mansa  river  (a 
tributary  of  the  Luapula),  eleven  in  the  vicinity  of  Lake  Mweru,  and 
thirteen  on  Lake  Tanganyika.  About  the  same  time,  we  found  three 
cases  in  villages  near  the  Luapula,  and  during  our  later  trip 
we  diagnosed  eighteen  more,  two  on  Lake  Mweru  and  sixteen  on 
Tanganyika.  With  a  few  additional  cases,  which  have  since  been 
found  by  the  various  medical  officers,  there  are  between  fifty  and  sixty 
known  ones  in  the  country. 
The  one  case  found  in  Nyasaland  has  an  interesting  history.  It 
15  that  of  a  boy  who  had  accompanied  his  master  from  that  country 
down  the  Congo  river  to  its  mouth.  From  there  he  had  gone  to  Cape 
Town,  and  finally  returned  to  his  home  by  way  of  the  Zambesi.  This 
illustrates  the  extent  to  which  some  of  these  natives  will  travel  in 
the  employ  of  Europeans. 
Only  four  of  our  cases  were  in  women.  The  remaining 
seventeen  were  in  males  varying  in  age  from  ten  to  forty  years.  The 
great  majority  of  them  were  adults.  With  the  exception  of  two,  in 
whom  clinical  symptoms  were  present,  all  were  apparently  quite 
healthy,  and  the  only  sign  observable  was  enlargement  of  the 
lymphatic  glands  in  the  neck.* 
Some  of  them  said  that  they  had  had  occasional  attacks  of  fever 
and  headache ;  others  that  they  had  not  been  ill  at  all.  Headache 
is,  however,  such  a  common  complaint  amongst  natives,  due  usually 
to  constipation,  that  no  attention  need  be  paid  to  it,  unless  it  is 
exceptionally  severe. 
*  These  cases  were  seen  only  once,  so  that  we  are  unable  to  say  whether  there 
were  any  slight  disturbances  of  the  body  temperature  or  the  pulse  which  may  he 
present  in  otherwise  apparently  normal  cases  of  the  disease.  So  far  as  we  cooW 
determine  at  the  time,  the  natives  we  found  to  be  infected  were  quite  free  from 
any  symptoms. 
