450  Field  Columbian  Museum — Reports,  Vol.  i. 
"The  steady  influx  of  specimens  rendered  an  increase  of  space  for 
cases  an  urgent  necessity  early  in  the  year,  and  an  extension  30  x  18 
feet  was  planned  and  built  over  the  east  gallery  adjoining  the  Cur- 
ator's office.  This  was  finished  and  ready  for  occupancy  early  in 
May.  It  has  three  large  north  windows,  and  accommodates  eighteen 
herbarium,  cases  of  the  new  construction  described  below,  twelve  of 
the  old  Bebbian  cases,  two  special  research  tables  and  a  long  dis- 
tributing table  as  well.  The  herbarium  now  has  a  total  of  sixty-eight 
cases,  containing  in  all  1,744  pigeon-holes.  Through  this  enlarge- 
ment the  storage  room  was  freed  of  much  accumulated  material,  and 
its  space  became  available  for  systematic  arrangement.  This  room 
now  contains,  besides  the  mounting  table  and  accessories,  a  continu- 
ous rack  bearing  sixteen  large  tin  cases  of  fifteen  pigeon-holes  each 
for  the  poisoning  and  storage  of  duplicates  preparatory  to  their  dis- 
tribution, and  eighteen  similar  cases  of  trays  for  the  storage  of  the 
larger  fruits  and  seeds  pertaining  to  the  herbarium  sheets.  All  of 
the  cases  in  the  herbarium  from  its  inception  have  been  constructed 
upon  a  principle  that  renders  them  as  nearly  air-tight  as  possible. 
The  interiors  are  so  arranged  that  a  two-inch  space  exists  between 
the  face  of  the  pigeon-holes  and  the  door,  and  a  like  space  between 
the  perpendicular  stops  at  their  back  and  the  back  of  the  case  itself. 
By  this  means  internal  circulation  is  complete,  and  as  much  insecti- 
fuge  as  may  be  deemed  advisable  can  be  thrown  through  between  the 
stops,  where  it  is  retained  free  of  the  pigeon-holes  at  the  bottom  of 
the  case.  Here  also  all  plant  detritus  automatically  collects  with  the 
withdrawal  and  insertion  of  the  plant  fascicles  as  they  are  used.  A 
half  round  groove,  one-quarter  of  an  inch  deep,  is  run  completely 
around  the  inner  face  of  the  door  frame,  which  fits  over  a  like  bead 
on  the  inner  stop;  this  renders  the  cases  insect  and  dust  proof.  The 
doors  are  glass  paneled,  affording  a  comprehensive  view  of  the  con- 
tents of  each  case,  thus  avoiding  the  necessity  of  referring  to  an 
index  when  locating  the  orders.  In  the  earlier  cases  two  semi-circu- 
lar spaces  were  cut  from  the  face  edge  of  the  shelves,  in  order  that 
the  fascicles  of  plants  might  be  readily  grasped  for  withdrawal  by  one 
or  both  hands.  This  method  is,  however,  open  to  strong  objection, 
as  the  frequent  grasping  of  the  bundles  breaks  the  plants  contained 
and  soils  the  genus  covers  as  well.  In  order  to  avoid  this  the  fol- 
lowing scheme,  converting  each  pigeon-hole  into  a  drawer,  has  been 
adopted  :  Sheets  of  heavy  straw-board,  one  inch  longer  than  the 
depth  of  the  pigeon-holes  and  slightly  narrower,  were  procured,  and 
a  strip  of  black  muslin  two  inches  wide  firmly  glued  on  the  face  of 
one  end.     The  reverse  side  was  then  scored  half  through  one  inch 
