2^7 
structure  could  be  made  out  in  it.  The  blepharoplast  is  rounded,  and 
is  usually  superimposed  on  the  nucleus.  There  is  no  visible 
undulating-  membrane,  and  the  flagellum  is  prolonged  into  a  well- 
deflned  free  portion.  The  protoplasm  stains  a  light  blue,  and  is  free 
from  granulations. 
This  type  of  parasite  is  not  nearly  so  frequent  as  the  one  previously 
described.  They  were  seen  in  preparations  made  from  a  fly  which 
had  fed  forty-eight  hours  beforehand  on  a  hen,  and  from  one  which 
had  fed  an  hour  earlier  on  a  monkey,  but  in  this  case  they  were  not 
so  long  as  the  ones  from  the  hen-fed  fl.y.  The  broad  forms  of  the 
organisms  were  also  present  in  these  preparations. 
The  more  usual  form  of  the  broad  type  approaches  in 
shape  that  of  the  ordinary  blood  trypanosomes.  They  measure 
from  ip/u  to  30/i  in  length  and  r8/r  to  3^  in  breadth.  The  posterior 
extremity  is  more  or  less  rounded  ;  the  anterior  end  is  attenuate.  The 
nucleus  is  oval,  and  stains  homogeneously.  The  blepharoplast  is 
rounded  or  oval  and  occupies  much  the  same  position  in  relation  to 
the  nucleus  as  in  the  long  forms.  The  undulating  membrane  is 
usually  perceptible.  The  flagellum  does  not  show  the  tendency  to 
become  clubbed,  which  was  noted  in  the  other  variety.  The  proto¬ 
plasm  stains  a  light  blue  or  pink,  and  may  contain  some  granules. 
Various  modifications  of  the  broad  type  exist,  and  the  ‘beaked’ 
kind  is  probably  one  of  them.  In  this  form,  the  posterior  extremity 
instead  of  being  rounded  in  the  ordinary  manner,  is  elongated,  so  that 
the  expanded  nuclear  area  occupies  a  central  position  between  two 
attenuated  portions.  The  posterior  extremity  is  not,  however,  extended 
into  a  filiform  portion  like  the  anterior  end,  but  is  usually  cut  off 
squarely.  In  other  respects  it  is  much  like  the  ordinary  broad  type. 
In  most  of  the  preparations,  oval  or  rounded  forms  measuring 
about  4/i  or  5^  m  diameter,  and  without  a  flagellum,  were  present. 
The  protoplasm  stains  darkly,  and  may  contain  granules.  These 
forms  are  apparently  derived  from  the  ordinary  broad  ones.  The 
posterior  portion  of  the  parasites  containing  the  nucleus  and 
blepharoplast  become  globular,  while  the  anterior  part  loses  its 
staining  powers,  becomes  irregular  in  shape,  and  degenerates.  The 
flagellum  disappears  coincidentally.  No  definite  retaining  wall  is 
present,  so  that  these  forms  are  not  true  cysts.  Encystment,  as 
described  by  Minchm,^  has  not  been  observed  in  our  preparations. 
