﻿222 
  Mr. 
  R. 
  C. 
  L. 
  Perkins 
  on 
  

  

  a 
  torpid 
  condition 
  from 
  the 
  herbage, 
  but 
  the 
  bad 
  weather 
  

   continued, 
  and 
  further 
  visits 
  on 
  the 
  fine 
  days 
  following 
  

   failed 
  to 
  yield 
  a 
  single 
  specimen. 
  In 
  the 
  early 
  spring 
  bees 
  

   seem 
  to 
  be 
  aware 
  of 
  these 
  coming 
  changes 
  of 
  weather, 
  and 
  

   vanish 
  as 
  if 
  by 
  magic 
  when 
  the 
  sun 
  disappears. 
  That 
  rarer 
  

   species 
  manage 
  to 
  survive 
  such 
  disastrous 
  climatic 
  changes 
  

   is 
  very 
  probably 
  due 
  to 
  the 
  fact 
  that 
  in 
  some 
  species, 
  and 
  

   perhaps 
  in 
  all, 
  a 
  percentage 
  of 
  individuals 
  do 
  not 
  emerge 
  

   in 
  the 
  normal 
  period, 
  but 
  remain 
  over 
  as 
  larvae, 
  to 
  become 
  

   developed 
  in 
  the 
  following 
  season. 
  This 
  occurs 
  not 
  only 
  in 
  

   cold 
  climates, 
  but 
  also 
  in 
  the 
  tropics, 
  and 
  must 
  be 
  of 
  great 
  

   advantage 
  for 
  the 
  continuance 
  of 
  a 
  species. 
  It 
  has 
  already 
  

   been 
  mentioned 
  that 
  some 
  species 
  of 
  Andrena 
  are 
  not 
  

   constant 
  in 
  their 
  habits 
  of 
  forming 
  compact 
  colonies, 
  nor 
  

   are 
  they 
  so 
  with 
  regard 
  to 
  their 
  choice 
  of 
  a 
  situation 
  for 
  

   these 
  colonies. 
  For 
  instance, 
  I 
  have 
  found 
  the 
  fine 
  A. 
  

   hattorfiana 
  forming 
  a 
  compact 
  colony 
  in 
  a 
  hard-trodden 
  

   pathway, 
  while 
  hard 
  by 
  others 
  were 
  burrowing 
  singly 
  in 
  

   places 
  where 
  the 
  gromid 
  was 
  well 
  covered 
  with 
  vegetation. 
  

   Again, 
  when 
  we 
  consider 
  the 
  plants 
  from 
  which 
  they 
  collect 
  

   the 
  pollen 
  and 
  honey 
  for 
  their 
  nests 
  and 
  procure 
  the 
  latter 
  

   for 
  their 
  food, 
  we 
  find 
  a 
  great 
  diversity 
  of 
  plants 
  chosen 
  by 
  

   the 
  individuals 
  of 
  some 
  species. 
  Also 
  a 
  flower 
  that 
  is 
  much 
  

   visited 
  in 
  one 
  locality 
  appears 
  to 
  be 
  nearly 
  or 
  quite 
  neg- 
  

   lected 
  in 
  another. 
  In 
  Suffolk 
  the 
  summer 
  brood 
  of 
  A. 
  

   bimaculata 
  was 
  found 
  on 
  one 
  occasion 
  in 
  great 
  numbers 
  on 
  

   the 
  flowers 
  of 
  Senecio 
  on 
  the 
  breck-sands, 
  whereas 
  in 
  Devon- 
  

   shire 
  I 
  have 
  been 
  through 
  acres 
  covered 
  with 
  these 
  flowers 
  

   where, 
  although 
  bimaculata 
  was 
  numerous, 
  not 
  one 
  was 
  

   observed 
  to 
  visit 
  them. 
  Smith 
  says 
  that 
  Nomada 
  * 
  rober- 
  

   jeotiana 
  is 
  to 
  be 
  sought 
  for 
  on 
  the 
  flowers 
  of 
  Senecio, 
  but 
  in 
  

   Devonshire 
  this 
  bee 
  visits 
  almost 
  exclusively 
  the 
  Potentilla, 
  

   even 
  though 
  ragwort 
  abounds 
  in 
  the 
  same 
  locality, 
  and 
  Mr. 
  

   Morice 
  informs 
  me 
  that 
  he 
  has 
  only 
  taken 
  it 
  on 
  this 
  flower. 
  

   Very 
  few 
  of 
  our 
  Andrenas 
  are 
  constant 
  to 
  a 
  single 
  or 
  one 
  or 
  

   two 
  species 
  of 
  plants, 
  but 
  there 
  are 
  many 
  that 
  have 
  a 
  

   marked 
  predilection 
  for 
  one 
  or 
  two. 
  A.florea 
  is, 
  as 
  is 
  well 
  

   known, 
  peculiarly 
  attached 
  to 
  the 
  bryony, 
  cingulata 
  to 
  the 
  

   speedwell 
  {Veronica), 
  humilis 
  and 
  fulvago 
  to 
  Hieracium, 
  cetii 
  

   and 
  hattorfiana 
  to 
  the 
  scabious. 
  Some 
  flowers 
  are 
  extremely 
  

   attractive 
  to 
  a 
  considerable 
  number 
  of 
  species, 
  chief 
  amongst 
  

   which 
  are 
  the 
  catkins 
  of 
  Salix, 
  together 
  with 
  the 
  flowers 
  

  

  * 
  = 
  tormentillae, 
  Alfk. 
  

  

  