20 
Spiders  Used  in  Medicine. 
f  Am.  Jour.  Pharm. 
\     January,  1921. 
period,  "Tarantism,"  a  contagious  disease  that  was  common  in 
southern  Europe,  especially  Italy,  was  believed  to  have  been  started 
by  the  bite  of  a  spider.  The  victims  of  this  disease  were  pos- 
sessed with  an  uncontrollable  desire  to  dance.  In  our  own  day 
and  among  our  own  people  it  is  not  unusual  to  blame  the  bite  of 
a  spider  for  swellings  or  itchings  of  unknown  origin,  but  when 
questioned  the  sufferer  is  invariably  unable  to  give  other  evidence 
that  a  spider  is  responsible  for  the  trouble,  than  the  usual  answer, 
"What  else  could  have  done  it?"  On  this  negative  evidence  the 
blame  is  fixed  for  about  one  hundred  per  cent,  of  the  "spider  bites" 
of  our  people. 
With  the  possible  exception  of  a  single  species  *  in  our  South- 
ern States,  and  the  true  tarantulas  of  the  Southwest,  it  seems  safe 
to  accept  that  there  are  no  spiders  in  our  country  whose  bite  need 
be  in  any  way  feared.  The  writer  has  handled  large  numbers  of 
our  native  spiders,  as  well  as  (during  excursions  in  the  tropics) 
hundreds  of  the  "banana  tarantulas,"  which  are  not  true  tarantulas, 
but  harmless  spiders  of  a  different  family.  True  tarantulas  may 
sometimes,  however,  be  found  in  banana  bunches.  In  no  case  has 
the  writer  been  bitten,  and  frequent  attempts  to  induce  spiders 
to  bite  the  tender  skin  between  his  fingers  resulted  in  failure. 
Others  who  have  made  this  experiment  with  success  report  that 
the  wound  inflicted  is  no  more  painful  than  a  slight  prick  with  a 
needle.  That  spiders  do  inject  a  virus  into  their  victims  is  indis- 
putable, but  it  is  in  quantities  sufficent  only  to  paralyze  an  insect. 
Besides,  it  is  injected  so  slowly  that  little,  if  any,  could  be  secreted 
during  the  short  interval  that  the  "jaws"  remain  in  the  wound  of 
an  animal  as  large  as  man. 
Spider  Web. — All  species  of  spiders  are  capable  of  spinning 
web,  though  far  from  all  spin  orbs  or  sheet-like  webs  for  entrapping 
prey.  Many  species  only  throw  out  a  "drag  line"  as  they  move  from 
place  to  place,  o'r  drop  from  surface  to  surface,  and  never  spin  a 
more  complex  web,  except  in  wrapping  their  egg  masses. 
The  web  material,  or  silk,  is  produced  in  large  glands  within 
the  spider's  abdominal  cavity.  In  the  glands  the  material  is  liquid 
or  mucilaginous,  but  (except  certain  parts  of  the  viscid  silk)  im- 
mediately hardens  on  exposure  to  the  air.   From  the  glands  it  passes 
*  Latrodectus  mactans,  a  jet-black  spider  with  markings  of  yellow  or 
red. 
