206 
North  American  Conifer ce. 
A.m.  Jour.  Pharnu 
April,  1896. 
internal  periderm.  Adjoining  these  on  the  interior  were  two  or 
three  layers  of  thin-walled  cells  arranged  in  radial  rows.  These 
were  succeeded  by  a  considerable  thickness  of  large-celled  paren- 
chyma, containing  lacunae  filled  with  air,  scattered  secretion  reser- 
voirs of  the  usual  kind  in  pines,  a  few  crystal  cells  and  numerous 
scattered  tannin  and  oleoresin  cells,  but  no  lignified  cells.  The 
bast  layer,  also  destitute  of  lignified  elements,  was  small-celled,  with 
the  cells  generally  arranged  in  radial  rows.  Secretion  cells  con- 
taining tannic  and  oleoresinous  matters  were  abundant  in  this  layer, 
but  less  conspicuous  in  size  than  those  of  the  last-described  species. 
The  cambium  and  wood  possessed  no  marked  peculiarities.  The  pith 
was  composed  of  both  thin- walled  parenchyma  and  sclerotic  cells,  and 
many  of  the  parenchyma  cells  were  heavily  charged  with  tannic  and 
oleoresinous  matters. 
The  kind  and  distribution  of  tannin  in  this  species  agreed  closely 
with  that  in  the  other  species  described.  It  was,  however,  richer  than 
most,  except  P.  palustris,  in  oleoresinous  matters,  these  abounding 
not  only  in  the  secretion  reservoirs,  but  also  in  the  parenchyma  of 
the  middle  and  inner  bark,  in  the  medullary  rays,  in  the  pith  and  in 
the  tracheids. 
The  tannin,  moisture  and  ash  were  estimated  in  a  specimen  of 
the  bark  of  the  loblolly  pine  collected  near  Atlanta,  Ga.,  October, 
1895,  with  the  following  results  : 
The  loblolly  pine  is  considerably  tapped  for  turpentine,  although 
it  does  not  yield  this  product  as  profitably  as  does  the  long-leaf 
pine.  With  the  increasing  scarcity  of  pine  lumber,  this  tree  is 
looked  on  with  more  favor  than  formerly.  While  its  lumber  decays 
rapidly  when  exposed  to  the  weather,  yet  it  is  the  only  building  and 
fencing  material  in  numerous  large  sections  of  the  Southern  United 
States.  When  used  for  indoor  work  it  lasts  well,  and  compares 
favorably  with  other  pine  lumber. 
CHEMICAL  COMPOSITION. 
Per  Cent. 
Moisture  
Ash  in  absolutely  dry  bark  . 
Tannin  in  absolutely  dry  bark 
9*55 
1-19  » 
I2'55 
ECONOMICS. 
