104 
of  deposit  obtainable  on  standing  or  centrifugalisation  was  extremely 
small.  In  Case  7a  it  appeared  of  a  brownish  colour  and  in  Case  n 
of  a  whitish  aspect,  but  its  colour  was  difficult  to  estimate  owing  to 
the  small  amount  obtainable  ;  in  the  former  case,  for  example,  if  a  ; 
sufficient  amount  of  deposit  had  been  available,  it  would  probably,  ; 
judging  from  its  microscopical  characters,  have  been  of  a  dark  ! 
reddish  brown  or  chocolate  colour.  The  deposit  consisted  principally  j 
of  dark  granular  casts,  which,  in  Case  7a,  were  just  visible  to  the  j 
naked  eye,  being  about  100  4  to  150  n  long  and  40  4  to  60  /u  broad  | 
Fig.  32.  Deposit  from  light  yellow-coloured  urine  of  Cnse  7a  (third  day,  during 
suppression  of  urine).  On  the  left  are  a  few  red  blood  cells.  In  the 
middle  are  two  large  casts  and  a  fragment  of  a  third,  containing 
large  coarse  granules,  closely  packed  and  bounded  externally  by 
epithelium  derived  from  the  collecting  tubules.  To  the  right  are  renal 
epithelial  cells  and  cell  masses.  Cp.  with  Figs.  28  and  29. 
Magnification  t8o  diameters. 
The  granules  were  of  more  or  less  spherical  form,  very  coarse,  having 
a  diameter  of  about  5/2,  of  a  dark  reddish  brown  colour,  in  their 
aggregated  condition  somewhat  resembling  blood  clot,  but  of  a 
deeper  colour,  and  were  densely  packed  together,  so  that  it  was 
sometimes  difficult  to  discern  the  outlines  of  the  individual  granules  ’ 
(Fig.  32).  No  fine  or  medium  sized  granules  were  observed.  The  1 
casts  were  covered  externally  with  a  layer  of  epithelium,  and  from  ‘ 
their  size  and  the  appearance  of  the  epithelium  it  is  clear  that  most 
of  these  casts  were  formed  in  the  ducts  of  Bertini  which  they  com¬ 
pletely  plugged.  In  addition,  masses  of  epithelial  cells  and  single 
