271 
The  parasites,  in  the  fresh,  appeared  to  be  of  various  sizes  and 
shapes.  Some  were  almost  filamentous,  others  were  attenuated  at 
either  extremity,  at  the  flagellar  end  more  markedly  so,  while  others 
again  approached  more  closely  the  ordinary  shape  of  the  pathogenic 
trypanosomes.  They  appeared  to  be  about  one  and  a  half  times  the 
diameter  of  the  proboscis  in  length. 
Parasites  were  generally  present  in  the  gut  at  the  same  time  as 
in  the  proboscis,  although  this  was  not  invariably  the  case.  In  at 
least  one,  no  trypanosomes  were  seen  in  the  intestine. 
Stained  frefarations. 
A  special  description  of  the  forms  seen  in  the  proboscis  is 
unnecessary,  as  they  correspond  closely  to  those  observed  in  the  gut. 
In  general  their  dimensions  are  less,  but  in  other  respects  the 
description  of  the  various  intestinal  types  applies  equally  well  to 
those  of  the  proboscis. 
The  beaked  variety  was  the  commonest,  and  after  that  the 
ordinary  broad  club-like  forms.  The  long  ribbon-like  type  was  not 
seen  in  stained  preparations,  though  a  few  forms  resembling  on  a 
small  scale  the  very  narrow  long  type  were  observed.  In  many  of  the 
forms  the  flagellum  did  not  stain  at  all,  and,  if  present,  was  extremely 
rudimentary. 
VIII.  FEEDING  EXPERIMENTS 
These  were  originally  undertaken  in  order  to  trace,  if  possible,  a 
development  of  the  ‘  wild  ’  trypanosomes  in  Glossina  pal  falls.  Many 
different  sources  of  food  were  used,  mammalian  and  avian,  and  the 
- 
Source  of  food 
Flies  fed 
Flies  examined 
Positive 
Present 
Dog 
6 
4 
0  j 
Monkey  ... 
Guinea-pig 
42 
2 
38 
2 
4 
0 
10-5  1  1 1-1% 
Sheep 
Hen  ... 
Hornbill . 
Darter  ... 
Small,  canary-like  bird  ... 
20 
17 
3 
I 
I 
iq 
17 
.3 
I 
I 
3 
2 
I 
T 
T 
>57' 
ii'6\ 
337  i  iz7% 
100 
100  ) 
