A  jammry js95.m"  1  Structure  of  Sanguinaria  Canadensis.  7 
these  rows  it  is  impossible  in  most  instances  to  demonstrate  any 
communication  between  the  cells.  The  transverse  partitions  between 
the  cells  are  in  fact  imperforate.  In  a  few  instances,  however,  par- 
ticularly in  the  inner  layer  of  the  bark,  there  is  demonstrable  con- 
nection between  the  secretion  cells  of  the  chains,  which  thus  form  a 
true  laticiferous  tissue,  essentially  like  that  occurring  in  many  other 
a      b  c  d  e 
Fig.  4. 
of  the  Papaveraceae,  though  of  course  much  less  complex  in  its 
development.  It  is  seldom  the  case  that  these  milk-tubes  are  more 
than  a  dozen  cells  long,  and  they  are  seldom  branching.  In  fact  we 
find  in  this  plant  the  form  of  laticiferous  tissue  called  "  complex,"  or 
"  reticulate,"  only  in  the  most  rudimentary  stages  of  its  develop- 
ment. It  plays  a  very  subordinate  part  in  holding  the  secretions  of 
the  plant ;  but  still,  to  the  morphologist  it  is  highly  significant,  as 
