"^NovfZ'erfmf*}        Insccts  Dcstructive  to  Books.  509 
size  of  the  insect  is  considered,  it  is  only  the  kaen  obsei-ver  who  will 
spy  them  as  they  scamper  across  the  printed  page.  Though  so 
small,  they  will  be  found  to  be  the  cause  of  a  great  deal  of  damage 
to  books. 
Man}^  investigators  think  that  the  greatest  damage  is  committed 
by  the  larger  forms,  whereas,  as  a  rule,  the  smaller  species,  in  pro- 
portion tO'  their  size,  consume  many  times  the  amount  of  food  as 
compared  to  that  of  the  larger  insect.  I  especially  noticed  this  in 
making  the  experiment  on  artificial  parchment  herein  mentioned, 
where  twelve  roaches,  many  of  them  females,  big  with  eggs,  at 
which  time,  of  course,  in  order  to  provide  the  necessary  supply  of 
food  for  the  coming  generation,  they  would  eat  more  than  before 
the  period  of  gestation,  ate  such  a  small  amount  of  the  paper  that  I 
spoke  about  it  to  a  gentleman  who  was  present  when  I  examined 
the  parchment.  A  fly  in  one  day  will  consume  food  equal  to  its  own 
weight.  This  is  also  illustrated  by  birds,  who,  in  proportion  to  man, 
eat  a  far  greater  quantity  of  food. 
Researches. — During  the  past  year,  I  have  made  a  number  of 
experiments,  and  much  against  my  will  have  arrived  at  the  con- 
clusion that  as  far  as  our  present  knowledge  of  the  effects  of 
poisons  on  these  small  forms  of  life  is  concerned,  we  have  not  even 
laid  the  foundation  upon  which  to  build. 
The  potato  bug  is  an  example.  The  paris  green  is  placed  on 
the  plant  in  the  morning,  but  at  night  the  bugs  are  still  there  and 
seem  to  be  eating  the  plant  with  more  voracity  than  when  it  was 
absent.  The  chemical  elements  in  the  air  and  plant  cause  a  reac- 
tion to  take  place,  by  which  the  poisonous  qualities  are  lost,  and 
instead  of  poison  to  kill,  a  substance  to  the  liking  of  the  insect  is 
produced,  as  I  discovered  during  my  experience  in  farming. 
Another  source  of  error  is  the  lack  of  positive  knowledge  as  to 
the  resistance  of  thesci  minute  forms  to  poisons,  heat,  pressure,  etc., 
in  their  early  stages.  I  have  been  taken  to  task  for  the  statement 
made  by  me  in  my  first  paper  as  to  mosquitoes  hatching  from  eggs 
that  have  lain  exposed  for  a  long  period  of  time,  but  I  think  that 
the  following  example  of  life  remaining  dormant  under  adverse 
conditions  is  more  wonderful. 
When  T  started  to  collect  insects,  T  used  for  a  cabinet  a  case  of 
drawers  which  had  been  kept  in  a  dry  room  of  my  home  and  had 
been  in  daily  use  for  about  twelve  years,  and  placed  it  in  an  outside 
shed,  the  atmosphere  of  which  was  warm  and  damp.    Some  time 
