close  connection  with  the  nucleus,  either  slightly  anterior  to  or  super¬ 
imposed  on  it.  No  definite  undulating  membrane  is  present,  and  the 
flagellum  is  co-terminous  with  the  prolonged  portion  of  the  parasite 
The  protoplasm  may  contain  a  few  granules,  and  usually  stains  a 
uniform  and  rather  deep  blue. 
The  oval  or  rounded  motionless  forms  are,  except  that  they  are 
devoid  of  flagellum,  practically  identical  with  the  ones  just  described 
which  are  apparently  derived  from  them  by  the  growth  of  the 
flagellum  and  coincident  lengthening  of  the  body.  As  in  the  case  of 
similar  forms  seen  in  Glossina  palfalis,  no  trace  of  a  cyst  wall  is 
present. 
Division  forms  are  present  amongst  parasites  of  the  broad  type. 
The  parasites  in  the  intestine  of  Glossina  morsitans  recall  closely 
those  of  Glossina  palpalis,  the  only  marked  difference  being  the 
almost  uniformly  posterior  position  of  the  blepharoplast,  and  the 
greater  tendency  to  acuity  in  the  posterior  part  of  the  body.  These 
differences  are  not  sufficiently  decided,  and  the  amount  of  work  we 
were  able  to  devote  to  the  study  is  too  small  to  enable  us  to  say  that 
they  are  a  different  species. 
B.  In  Proboscis. 
Fresh  preparations. 
In  the  proboscis  of  freshly-caught  flies  the  parasites  were  found,  as 
noted  by  Roubaud,^  adhering  to  the  labium  and  labrum  in  large 
clumps,  and  occasionally  so  numerous  as  apparently  to  occlude  the 
lumen.  Moreover,  we  observed  them  frequently  within  the  hypo- 
pharynx  also,  in  extremely  large  numbers.  In  both  situations,  the 
clumps,  which  resembled  a  chrysanthemum,  were  formed  of  very 
many  parasites  which  had  the  flagellar  extremity  directed  towards 
the  walls  of  the  proboscis.  They  moved  with  a  slow  wave-like  action, 
and  also  by  contraction.  Single,  separate  organisms  were  fairly 
active,  and,  as  described  by  Roubaud  frequently  became  attached  to 
the  slide  or  to  bits  of  tissue  in  the  preparation.  As  a  rule, 
they  were  present  throughout  the  whole  length  of  the  proboscis, 
though  variations  were  noticed  from  a  decided  massing  of  the 
parasites  at  the  distal  extremity  to  a  scanty  occurrence  at  the 
proximal  end. 
