289 
Several  years  later  (1734-42)  Reaumur,  in  France,  published 
very  careful  and  mostly  new  observations  about  many  insects  and 
their  parasites,  and  in  Switzerland  de  Geer  (1752-78)  studied 
also  with  great  care  and  with  great  genius  insects  in  general,  in- 
cluding parasites  and  gave  with  his  classic  work,  ‘‘Memoirs  pour 
Servir  a THistoire  des  Insects”  one  of  the  strongest  impulses  to 
entomology. 
At  the  end  of  the  eighteenth  and  beginning  of  the  nineteenth 
century  the  study  of  systematic  Zoology  flourished  and  many 
works  descriptive  of  insect  parasites  were  published,  among  them 
are  recorded  particularly  those  of  Dalman,  Nees,  Gravenhorst, 
Walker,  Westwood,  Foerster,  and  for  Italy  those  of  Spinola  and 
Desideri. 
But  the  one  who  excelled  by  works  of  great  value  (1837-52) 
about  insects  injurious  to  forests  and  their  parasites  and  who 
recognized  the  full  importance  of  the  latter  in  fighting  the  former, 
was  the  German,  J.  T.  C.  Ratzeburg.  To  his  works  we  refer 
even  today  as  to  an  inexhaustive  mine  of  observations  of  great 
usefulness.  But  we  do  not  agree  with  him  that  man  cannot  in 
some  way  hinder  the  development  of  certain  parasites. 
2 The  first  who  to  my  knowledge  not  only  divined  the  import- 
ance of  the  parasite  phenomenon,  but  also  applied  it  successfully, 
was  the  Frenchman,  Boisgiraud  of  Poitiers.  About  the  year 
1840  he  freed  the  poplars  along  a promenade  in  the  suburbs  of 
his  town  of  Liparis  dispar  by  placing  there  Calosoma  sycophanta; 
besides  be  destroyed  Fordculids  in  his  own  garden  using  Staphy- 
linus  oleus,  while  he  obtained  no  result  with  Carabas  auratus 
against  the  same  insect,  for  reasons  which  he  was  afterwards  able 
to  explain.  The  results  of  these  experiments  of  Boisgiraud  were 
published  in  Joly  in  1843  m the  “Revue  Zoologique”  of  the  “So- 
cieta  Carvieriana”  of  Paris. 
This  new  method,  original  and  inviting,  traced  in  the  domain 
of  therapy,  which  then  more  than  now  groped  in  a confusion  of 
empirical  methods,  inspired  in  April,  1843,  the  technical  com- 
mission of  the  society  for  the  encouragement  of  arts  and  crafts 
of  Milan  to  offer  as  premium  a gold  medal  to  be  given  in  1845 
to  the  one  who  shall  have  in  the  meantime  successfully  experi- 
mented with- artificial  breeding  of  some  carnivorous  insects,  which 
may  be  utilized  to  advantage  for  the  destruction  of  another  species 
of  insects  recognized  as  injurious  to  agriculture. 
This  is  a subject  which  would  seem  to  have  been  dealt  with 
each  in  the  present  century  rather  than  in  1843. 
To  this  appeal  of  the  meritorious  society  enlightened  and  singu- 
lar for  its  time,  responded  Antonio  Villa,  already  favorably  known 
2 From  here  to  line  . . page  . . is  entirely  reproduced  from  a recent 
nublication  of  Prof.  Trotter,  "Two  Precursors  in  the  Application  of 
Carnivorous  Insects-  for  the  Defense  of  Cultivated  Plants.”  Eedia  V., 
126-132. 
