Various  other  areas  deserve  particidar  notice:  for  instance
oval  or  ring  furms.  which  are  of  the  shape  of  a  hyaline  malaria  rinM
with  a  circular  refractive  centre;  these  sometimes  have  a  definite  crca-
cent  shape,  and  are  famous  since  once  described  as  the  parasite  i.>/'
mefislcs.  and  more  reccnily  as  that  of  spotted  fever  (sec  .Vnderwin's
figures).  What  these  areas  are  is  not  clear:  they  change  shape  in  3
peculiar  way:  they  do  not  increase  in  number  or  grow  larger  011
standing;  llicy  occur  in  the  greatest  variety  of  conditions,  but  esft-
cially  in  measles  (see  Fig.  93.  6).
In  other  cells  are  rod-like  areas  resembling  bacilli,  c.  Thoe
"  bacilli"  may  keep  up  a  con.stant  vibratory  motion,  moving  practtcalty
through  the  whole  substance  of  the  cell,  and  hence  the  mistake  some-
times inaile  of  suggesting  cultures  to  isolate  this  organism  is  not  to  be
wondered  at.  We  remember  one  physician  who  was  confident  that
these  were  tj-phoid  bacilli  within  the  cells.  Others  si>eak  of  them  as
"  splits"  in  the  cell.
