﻿226 
  Mr. 
  R. 
  C. 
  L. 
  Perkins 
  on 
  

  

  these 
  bees, 
  and 
  it 
  is 
  quite 
  possible 
  that 
  not 
  all 
  the 
  individuals 
  

   that 
  one 
  sees 
  in 
  the 
  summer 
  of 
  a 
  double-brooded 
  species 
  are 
  

   really 
  the 
  offspring 
  of 
  a 
  spring 
  parent 
  ; 
  for 
  it 
  may 
  be 
  that 
  

   some 
  of 
  the 
  offspring 
  of 
  the 
  summer 
  brood 
  do 
  not 
  emerge 
  

   till 
  the 
  following 
  summer, 
  and 
  hkewise 
  that 
  some 
  of 
  the 
  

   spring 
  brood 
  have 
  also 
  taken 
  a 
  complete 
  year 
  before 
  they 
  

   have 
  emerged. 
  The 
  somewhat 
  perplexing 
  aberrations 
  one 
  

   finds 
  in 
  these 
  dimorphic 
  species 
  may 
  possibly 
  be 
  due 
  to 
  

   such 
  variations 
  in 
  the 
  time 
  occupied 
  in 
  development. 
  In 
  

   any 
  case 
  these 
  double-brooded 
  species 
  are 
  of 
  the 
  greatest 
  

   interest, 
  and 
  so 
  far 
  they 
  have 
  been 
  at 
  the 
  best 
  very 
  super- 
  

   ficially 
  studied. 
  Some 
  thirty 
  years 
  ago 
  Edward 
  Saunders 
  

   intended 
  to 
  study 
  them 
  specially 
  and 
  pubUsh 
  his 
  observa- 
  

   tions, 
  but 
  unfortunately 
  he 
  did 
  not 
  (so 
  far 
  as 
  I 
  am 
  aware) 
  

   carry 
  out 
  his 
  intention. 
  One 
  other 
  point 
  which 
  must 
  be 
  

   considered 
  in 
  connection 
  with 
  the 
  spring 
  Andrenas, 
  which 
  

   produce 
  only 
  a 
  single 
  brood, 
  is 
  the 
  fact 
  that 
  in 
  many 
  cases, 
  

   though 
  there 
  is 
  no 
  second 
  emergence, 
  the 
  fully 
  developed 
  

   bee 
  has 
  left 
  the 
  pupa 
  the 
  same 
  year 
  that 
  the 
  egg 
  was 
  laid 
  

   by 
  the 
  parent, 
  and 
  possibly 
  even 
  before 
  the 
  end 
  of 
  the 
  sum- 
  

   mer. 
  Consequently, 
  the 
  difference 
  in 
  the 
  actual 
  period 
  of 
  

   development 
  between 
  some 
  of 
  the 
  single-brooded 
  species 
  we 
  

   capture 
  in 
  the 
  spring 
  and 
  the 
  examples 
  of 
  other 
  species, 
  which 
  

   are 
  the 
  offspring 
  of 
  a 
  second 
  brood 
  of 
  the 
  preceding 
  year, 
  

   is 
  not 
  nearly 
  so 
  great 
  as 
  may 
  have 
  been 
  imagined, 
  but 
  the 
  

   conditions 
  of 
  temperature, 
  etc., 
  may 
  be 
  different 
  and 
  of 
  im- 
  

   portance. 
  We 
  know 
  from 
  Smith's 
  observations 
  that 
  in 
  the 
  

   case 
  of 
  some 
  bees, 
  such 
  as 
  Anthophora, 
  some 
  individuals 
  

   pass 
  the 
  winter 
  as 
  larvae, 
  and 
  pupate 
  and 
  produce 
  mature 
  

   bees 
  in 
  the 
  following 
  year, 
  while 
  others 
  are 
  already 
  fully 
  

   mature 
  on 
  the 
  approach 
  of 
  winter, 
  and, 
  in 
  fact, 
  are 
  occasion- 
  

   ally 
  dug 
  up 
  in 
  that 
  condition 
  during 
  the 
  winter 
  months. 
  In 
  

   the 
  case 
  of 
  Anthophora 
  this 
  does 
  not 
  appear 
  to 
  lead 
  to 
  any 
  

   noticeable 
  variation. 
  When 
  we 
  find 
  examples 
  of 
  either 
  

   brood 
  of 
  such 
  a 
  species 
  as 
  A. 
  dorsata 
  exactly 
  resembling 
  

   one 
  another, 
  while 
  others 
  have 
  quite 
  differently 
  coloured 
  

   legs, 
  at 
  present 
  we 
  do 
  not 
  know 
  v^hether 
  these 
  different 
  

   varieties 
  have 
  really 
  taken 
  very 
  different 
  periods 
  of 
  time 
  

   for 
  their 
  development, 
  a 
  few 
  months 
  in 
  one 
  case 
  and 
  many 
  

   months 
  in 
  the 
  other, 
  or 
  whether 
  those 
  which 
  are 
  aUke 
  

   may 
  or 
  may 
  not 
  have 
  taken 
  the 
  same 
  period 
  to 
  become 
  

   mature. 
  

  

  Of 
  other 
  variations 
  one 
  may 
  mention 
  that 
  m 
  which 
  either 
  

   the 
  scopae 
  or 
  the 
  anal 
  fimbria 
  or 
  one 
  of 
  these, 
  instead 
  of 
  

  

  