"""•/urxBSo""}  Structure  of  Bye-Woods.  349 
2.  The  inferior  varieties  of  Red-wood  from  America  are  in  structure 
intimately  connected  with  the  Blue-wood,  Their  color,  however,  dis- 
tinguishes them,  more  or  less  readily,  from  the  latter.  In  relation  to 
structure  and  remaining  properties,  the  Lima  Red-wood  (Caesalpina. 
crista?),  Nicaragua  Red-wood  (C.  brasiliensis)  and  others  are  not  rep- 
resented with  accuracy. 
Without  the  lens  neither  medullary  rays  nor  annual  growths  are  dis- 
cernible on  a  cross  section.  The  ducts  are  not  at  all,  or  only  partially,, 
visible.  The  arrangement  of  the  parenchyma  (Fig.  3)  is  the  same  as 
in  the  Campeachy-wood,  only  the  structure  is  finer.  The  parenchy- 
mous  spots  appear  more  combined,  and  drawn  out  more  delicately  at 
their  ends. 
In  the  tangential  section  the  ducts  appear  as  dark  lines,  and  the 
medullary  rays  are  very  short  and  delicate  longitudinal  lines,  which  are 
not  (as  with  Brazil-wood)  disposed  in  horizontal  series.  On  a  radial 
section  are  seen  the  medullary  rays,  0*3  mm.  wide.  These,  with  refer- 
ence to  their  width,  may  be  classed  as  between  the  Brazil-  and  Sapan- 
wood.  Under  the  lens,  the  cross  section  gives  us  Fig.  3.  We  notice 
here  the  duct  openings,  0'i\  to  o*i  mm.  in  width,  and  the  very  irregu- 
larly developed  medullary  rays,  while  true  annual  rings  are  not  to  be 
seen.  The  tangential  sections  show,  especially  in  the  poorer,  lighter- 
colored  species,  the  medullary  rays  very  distinctly,  as  dark  longitudinal 
strokes,  which  are  irregularly  divided,  so  that  a  wave  appearance  (Bra- 
zil- and  Sandai-wood)  is  not  produced.  This  is  not  even  noticed  in  the 
radial  section.  The  medullary  rays  occur  mostly  as  short,  broad  cross 
bands,  the  ducts  as  shining,  dark  half  tubes. 
3.  The  Brazil,  Sapan  and  Coulteria  Red-wood  agree  with  each 
other  in  the  essential  peculiarities  of  their  structure.  They  all,  for 
example,  possess  almost  equally  distributed  duct  pores,  and  round  and 
very  characteristic  parenchymous  spots. 
Of  all  the  red-woods,  the  Coulteria  Red-wood  (Coulteria  tinctoria) 
has  the  finest  structure.*  Its  cross  section  presents  almost  exactly  the 
same  appearance  as  the  Brazil-wood,  only  the  annual  rings  are  more 
distinct  and  the  wood  is  colored  more  of  a  brown  than  a  red.  The 
tangential  and  radial  sections  are  about  the  same  as  in  the  Brazil- 
wood. 
The  Brazil-wood  presents  in  its  cross-section  a  reddish-brown,  hard, 
shining  background,  in  which  are  noticed  innumerable  scattered  pale 
red  points.     Many  of  these  are  indistinct  and   blurred.     Without  a. 
