﻿380 
  JOURNAL 
  OF 
  THU 
  WASHINGTON 
  ACADEMY 
  OF 
  SCIENCES 
  VOI.. 
  12, 
  NO. 
  16 
  

  

  Fig. 
  5-9 
  in 
  other 
  situations. 
  Larval 
  mononchs 
  , 
  were 
  only 
  able 
  to 
  

   attack 
  and 
  destroy 
  the 
  prey 
  in 
  the 
  way 
  described, 
  but 
  even 
  a 
  small 
  

  

  mononch 
  will 
  attack 
  prey 
  of 
  much 
  larger 
  size. 
  

   Large 
  mononchs 
  often 
  swallow 
  smaller 
  nemas 
  

   whole 
  ; 
  this 
  will 
  happen, 
  if 
  the 
  prey 
  is 
  seized 
  

   at 
  one 
  end 
  of 
  the 
  body, 
  the 
  animal 
  being 
  

   then 
  sometimes 
  swallowed 
  without 
  being 
  

   killed 
  or 
  even 
  injured 
  by 
  the 
  mouth 
  organs 
  of 
  

   the 
  mononch. 
  In 
  our 
  slide 
  cultures 
  this 
  phe- 
  

   nomenon 
  was 
  twice 
  observed. 
  A 
  large 
  adult 
  

   mononch 
  swallowed 
  a 
  rather 
  large 
  larva 
  of 
  

   Rhabditis 
  elegans. 
  In 
  this 
  species 
  of 
  Rhab- 
  

   ditis 
  the 
  larvae 
  are 
  very 
  slender 
  and 
  more 
  

   resistant 
  than 
  other 
  species. 
  The 
  larva 
  

   seemed 
  to 
  have 
  passed 
  through 
  the 
  mouth 
  

   and 
  oesophagus 
  of 
  the 
  mononch 
  without 
  

   harm, 
  probably 
  in 
  the 
  way 
  sketched 
  in 
  

   Fig. 
  10. 
  We 
  first 
  noticed 
  that 
  the 
  mononch, 
  

   very 
  active 
  the 
  day 
  before, 
  appeared 
  nearly 
  

   motionless. 
  To 
  our 
  great 
  astonishment 
  we 
  

   noticed 
  the 
  larva 
  of 
  the 
  Rhabditis 
  moving 
  

   throughout 
  the 
  intestine 
  as 
  if 
  searching 
  

   every-where 
  for 
  an 
  exit. 
  The 
  larva 
  moved 
  in 
  

   every 
  possible 
  direction, 
  the 
  mononch 
  be- 
  

   coming 
  less 
  active 
  all 
  the 
  time. 
  We 
  were 
  

   very 
  interested 
  in 
  knowing 
  the 
  outcome 
  of 
  

   this 
  case. 
  The 
  digestive 
  fluid 
  in 
  the 
  intestine 
  

   of 
  the 
  mononch 
  did 
  not 
  seem 
  to 
  harm 
  the 
  

   larva. 
  The 
  same 
  evening, 
  the 
  

   mononch 
  did 
  not 
  react 
  to 
  outside 
  

   stimuli 
  and 
  appeared 
  quite 
  motion- 
  

   less 
  . 
  During 
  the 
  night 
  the 
  Rhabditis 
  

   found 
  a 
  way 
  to 
  freedom 
  through 
  

   the 
  vulva 
  opening, 
  and 
  in 
  the 
  morn- 
  

   ing 
  the 
  mononch 
  was 
  dead. 
  The 
  

   same 
  thing 
  happened 
  shortly 
  after- 
  

   ward 
  with 
  another 
  very 
  active 
  

   mononch. 
  

  

  From 
  a 
  scientific 
  point 
  of 
  view 
  these 
  incidents 
  are 
  of 
  interest, 
  as 
  

   they 
  show 
  that 
  this 
  species 
  of 
  Rhabditis 
  is 
  very 
  resistant 
  to 
  mononch 
  

  

  Fig. 
  6. 
  Sketch 
  of 
  the 
  head- 
  

   end 
  of 
  a 
  mononch 
  seizing 
  

   an 
  adult 
  Rhabditis 
  by 
  

   the 
  neck. 
  The 
  skin 
  of 
  

   the 
  prey 
  is 
  already 
  

   opened, 
  and 
  the 
  mo- 
  

   nonch 
  is 
  sucking 
  the 
  

   contents 
  ; 
  notice 
  that 
  the 
  

   dorsal 
  tooth 
  during 
  this 
  

   sucking 
  action 
  is 
  in 
  its 
  

   normal 
  position 
  and 
  not 
  

   protruded. 
  The 
  prey 
  

   was 
  afterwards 
  sucked 
  

   out 
  as 
  shown 
  in 
  Fig. 
  9. 
  

  

  Fig. 
  7. 
  Sketch 
  of 
  a 
  Rhabditis 
  seized 
  near 
  

   the 
  middle 
  of 
  the 
  body 
  and 
  partly 
  

   sucked. 
  See 
  Fig. 
  8 
  for 
  later 
  stage. 
  

  

  