﻿366 
  

  

  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1922. 
  

  

  The 
  large 
  amount 
  of 
  dirt 
  carried 
  up 
  from 
  below 
  and 
  spread 
  before 
  

   the 
  entrance 
  gives 
  indication 
  that 
  the 
  burrow 
  is 
  a 
  long 
  one 
  and 
  leads 
  

   far 
  into 
  the 
  earth 
  ; 
  and, 
  indeed, 
  Philanthus, 
  with 
  her 
  tarsi 
  and 
  man- 
  

   dibles, 
  often 
  digs 
  a 
  shaft 
  that 
  is 
  2 
  feet 
  or 
  more 
  in 
  length. 
  From 
  one 
  

   edge 
  of 
  the 
  pile 
  of 
  sand 
  a 
  narrow, 
  tortuous 
  tunnel 
  descends 
  obliquely 
  

   into 
  the 
  earth 
  for 
  about 
  6 
  inches, 
  then 
  swings 
  .around 
  to 
  run 
  in 
  a 
  

  

  horizontal 
  direction 
  for 
  15 
  more, 
  and 
  finally 
  

   ends 
  in 
  a 
  neatly 
  rounded 
  oval 
  cell 
  (fig. 
  3). 
  

   Other 
  cells 
  are 
  disclosed, 
  but 
  these 
  have 
  no 
  

   direct 
  communication 
  with 
  the 
  main 
  corri- 
  

   dor. 
  From 
  their 
  contents 
  we 
  gain 
  a 
  clue 
  to 
  

   the 
  plan 
  of 
  the 
  architect. 
  The 
  chamber 
  

   closest 
  to 
  the 
  entrance 
  is 
  strewn 
  with 
  the 
  

   skeletons 
  of 
  Halictine 
  bees, 
  and 
  on 
  this 
  heap 
  

   rests 
  the 
  consumer's 
  cocoon. 
  We 
  break 
  into 
  

   the 
  next 
  cell 
  and 
  find 
  a 
  full-grown 
  larva 
  

   munching 
  its 
  last 
  mouthfuls 
  of 
  bee 
  flesh. 
  

   The 
  succeeding 
  cells 
  show 
  us 
  larvae 
  growing 
  

   fat 
  on 
  their 
  provisions, 
  each 
  larva 
  a 
  little 
  

   younger 
  and 
  smaller 
  than 
  the 
  preceding. 
  

   The 
  penultimate 
  pocket 
  contains 
  the 
  wasp's 
  

   egg, 
  while 
  the 
  terminal 
  cell 
  is 
  as 
  yet 
  unpro- 
  

   visioned. 
  From 
  this 
  arrangement 
  it 
  is 
  clear 
  

   that 
  the 
  oldest 
  cell 
  is 
  the 
  one 
  nearest 
  the 
  

   opening 
  of 
  the 
  burrow. 
  Each 
  cell 
  was 
  in 
  

   turn 
  a 
  terminal 
  pocket 
  which 
  was 
  fashioned 
  

   only 
  when 
  needed. 
  After 
  completion 
  its 
  

   connection 
  with 
  the 
  main 
  gangway 
  was 
  

   blocked 
  and 
  the 
  gallery 
  was 
  pushed 
  onward 
  

   to 
  form 
  another 
  pocket. 
  In 
  due 
  time 
  this 
  

   was 
  likewise 
  provisioned, 
  tenanted, 
  and 
  

   sealed, 
  and 
  so 
  the 
  work 
  proceeded 
  until 
  the 
  

   wasp 
  had 
  enough 
  separate 
  nurseries 
  to 
  

   house 
  her 
  entire 
  offspring. 
  

  

  The 
  illustration 
  (fig. 
  3) 
  is 
  meant 
  to 
  repre- 
  

   sent 
  a 
  typical 
  burrow. 
  Scores 
  of 
  nests 
  were 
  

   excavated 
  and 
  all 
  conformed 
  more 
  or 
  less 
  to 
  

   this 
  general 
  type 
  in 
  inverse 
  proportion 
  to 
  the 
  stony 
  nature 
  of 
  the 
  

   ground. 
  One 
  wasp 
  had 
  met 
  with 
  so 
  many 
  obstacles 
  that 
  the 
  terminus 
  

   of 
  her 
  burrow 
  was 
  only 
  2 
  inches 
  from 
  the 
  entrance 
  — 
  she 
  had 
  tunneled 
  

  

  in 
  a 
  circle. 
  

  

  THE 
  EGG 
  AND 
  LARVA. 
  

  

  The 
  egg 
  of 
  the 
  Philanthus 
  (pi. 
  1, 
  fig. 
  2) 
  is 
  a 
  smooth, 
  banana- 
  

   shaped 
  capsule, 
  lustrous 
  white, 
  with 
  a 
  very 
  thin, 
  transparent 
  chorion. 
  

   Its 
  length 
  is 
  between 
  3 
  and 
  4 
  millimeters 
  ; 
  its 
  greatest 
  width 
  is 
  about 
  

  

  Pig. 
  2. 
  — 
  Philanthus 
  gibbosus. 
  

   Fore 
  tibia 
  and 
  tarsus 
  of 
  

   female. 
  (X 
  36.) 
  

  

  