369 
majority  of  forms  seen  were  in  a  state  of  active  multiplication,  so 
accounting  for  the  average  length  of  1575  /“•  The  mean  length  of 
single  individuals  was  13-15  //.  In  these  latter  the  cytoplasm  was 
relatively  clear  and  homogeneous,  the  blepharoplast  some  0-5  fx  from 
the  rounded  or  bluntly  angular  extremity ;  the  nucleus  rounded  and 
rather  loose  in  texture  being  centrally  placed.  There  is  a  slightly 
better  development  of  the  rudimentary  undulating  membrane  than 
is  usual  in  these  ‘  tadpole  ’  trypanosomes,  but  practically  no  free 
flagellum. 
In  divisional  forms  the  aflagellar  extremity  was  more  pointed,  and 
vacuoles  were  seen  in  the  cytoplasm  of  many.  The  undulating 
membrane  was  better  developed,  amounting  almost  to  that  common 
in  T.  lewisi,  and  a  free  extremity  to  the  flagellum  of  2  or  3  //  was 
seen  in  several  individuals.  Where  this  portion  could  not  be 
designated  ‘free,’  this  extremity  of  the  body  or  the  ectoplasm  was 
drawn  out  more  than  in  the  smaller  single  forms. 
(2)  Goat.  In  this  animal  the  trypanosomes  which  appeared 
measure  from  14-5  to  17-25  (average  15-97  A*)  in  length  and  1-5  to 
2-6^  in  breadth  (average  1-83  fx).  The  following  is  the  mean  of  a 
series  of  measurements  :  — 
Extremity  to  Blepharoplast  Nucleus  to 
Blepharoplast  to  Nucleus  Nucleus  flagellar  e.xtreraitv 
1-4  4-6  2-47  7-5 
No  free  flagellum  was  seen,  but,  as  ' in  the  pig,  the  flagellar 
extremity  of  the  body  was  in  some  cases  drawn  out.  The  cytoplasm 
stained  rather  pink,  and  granules  or  vacuoles  were  infrequent.  The 
aflagellar  extremity  is  rounded,  but  more  elongated  than  in  the 
tadpoles  of  T.  congolense.  Dividing  forms  (up  to  17-25  //)  were 
present,  and  in  these  there  is  some  approach  to  a  very  small 
undulating  membrane,  which  in  the  solitary  individual  is  as  rudimen¬ 
tary  as  in  ‘  tadpoles.’ 
Diagnosis 
From  the  morphology  of  this  trypanosome  it  would  appear  that 
we  are  dealing  with  either  T.  congolense  or  T .  namtrn.  The  animal 
experiments  are  limited,  but  a  dog,  a  rabbit  (at  Pretoria),  a  guinea-pig 
and  a  white  rat  remained  healthy  after  large  doses  of  heavily  infected 
