AmAii°ust,  1913  m' }   Nature  and  Structure  of  Cochineal.  349 
yet  I  was  now  more  than  ever  assured  that  not  only  the  insect  which 
produces  the  cochineal,  but  also  those  others  which  I  have  just 
mentioned,  are  formed  from  maggots  or  caterpillars. 
Leeuwenhoek  then  ascertained  that  the  rings  or  creases  which 
occur  in  the  commercial  cochineal  are  accidentally  produced  in  the 
drying,  and  concludes  that  the  cochineal  insect  is  composed  of  four- 
teen joints,  rings,  or  articulations.  Furthermore  he  says  that  after  he 
left  the  grains  of  cochineal  in  water  for  twenty-four  hours  or  more 
he  observed  that  the  cavity  which  had  been  caused  by  the  drying, 
was  swelled  and  extended  to  its  original  shape,  so  that  the  grains 
appeared  exactly  to  agree,  in  form  and  make,  with  the  hinder  part 
of  those  insects  whose  wings  and  bodies  are  covered  with  shells 
or  cases.  While  in  some  respects,  considering  the  time  when  they 
were  made,  Leeuwenhoek's  observations  seem  nothing  short  of 
remarkable,  it  is  probably  nearer  the  truth  when  we  say  that  he 
was  a  fortunate  observer  with  unusual  insight.  He  had  a  scientific 
mind  and  used  his  reasoning  faculties  with  remarkable  success,  so 
that  many  of  his  observations  form,  the  starting  point  for  very  much 
scientific  work.  Since  his  time  the  male  and  female  insect  have  been 
described  and  they  are  illustrated  in  a  number  of  works  on  ento- 
mology as  well  as  in  some  of  the  encyclopedias.  The  best  illus- 
trations of  the  male  and  female  insects  will  be  found  in  the  article 
by  Raphael  Blanchard.20 
Before  taking  up  the  structure  of  the  insect  it  may  be  well  to  say 
something  about  its  position  among  insects  and  to  consider  some  of 
the  facts  known  concerning  its  developmental  history. 
Cochineal  Insect  and  its  Habitat. 
The  cochineal  insect  belongs  to  the  order  Hemipterce,  suborder 
Homoptera,  Family  Coccidce.  The  latter  includes  the  scale-like  in- 
sects which  are  characterized  by  the  fact  that  the  wingless  female 
dies  shortly  after  producing  her  eggs,  the  latter  being  covered  up 
by  her  dead  scale-like  body.3  In  the  case  of  the  cochineal  insect 
the  larvae  are  found,  as  will  be  shown  later  on,  within  her  inflated 
body.  In  the  group  of  the  Coccidcz  we  find  a  number  of  interesting 
scale  insects.  Here  we  find  the  lac  insect  from  which  stick-lac  of 
commerce  is  produced,  the  latter  being  a  resinous  substance  ex- 
creted by  a  species  of  Coccus  (Carteria)  lacca  which  inhabit  the 
branches  of  several  tropical  trees.    From  the  bodies  of  these  in- 
