Tuna  is  a  Spanish-American  name  given
to  several  Opuntias,  but  botanists  have
adopted  it  as  the  scientiflcnamc  of  aslngle
species,  O.  Tuna,  a  native  of  various  parts
of  America,  from  Quito  to  Mexico  and  the
West  Indies,  from  some  of  which  countries
it  has  been  Introduced  into,  and  now  grows
abundantly  In,  Southern  Europe,  Northern
Africa,  the  Canaries,  Madeira,  &c.  It  is
one  of  the  tallest  growing  species,  having,
when  old,  an  erect  woody  stem  sometimes
as  much  as  twenty  feet  high,  and  jointed
branches  from  four  to  eight  or  more  inches
long,  of  an  oval  or  oblongform,  and  having
distant  bundles  of  spines  growing  from
bristly  cushions,  each  bundle  consisting  of
from  four  to  six,  or  sometimes  fewer,  stiff
unequal  spreading  yellowish  spines.  It
has  dull  reddl8h-K>range  flowers,  and  pro-
durcs  pear-Rhaped  fleshy  fruits  two  or  three
Inches  long  and  of  a  rich  carmine  colour
when  ripe.    The  Tuna,  on  account  of  Its


prickly  nature.  Is  much  usQd  for  bedgesr
and  In  Mexico  it  is  cultivated  for  retmng
the  cochineal  Insect  (see  Nopalea),  besides
which  several  parts  are  turned  to  useful
account.  The  sweet  juicy  fruits,  called
Prickly  Pears,  are  extensively  eaten  and
greatly  esteemed  for  their  cooling  proper-
ties; they  contain  an  abundance  of  aao
charlne  matter,  and  sugar  bas  been  made
from  them  In  Sicily ;  at  Naples  their  juice
Is  used  as  a  water-colour,  and  In  the  West
Indies  for  colouring  confectionery ;  while
In  Mexico  »  beverage  called  Ck>llncbe  is
prepared  from  them.  The  old  branches  and
stems  contain  a  network  consisting  of  an-
nual layers  of  hard  woody  fibres,  of  which
the  French  In  Algiers  make  various  orna-
mental articles,  such  as  vases,  fancy  bas-
kets, flower-trays,  &c.«  and  even  use  it  for
veneering.
