3.  Disease  of  the  lateral  columns  usualh'  decreases  the  skin  reflexes,
especially  those  of  the  trunk.  This  is  particularly  true  of  the  so-called
descending  degeneration  of  these  columns,  which  follows  the  development
of  cerebral  lesions.
4.  Sclerosis  of  the  lateral  columns  always  increases  the  "deep"  or
tendon  reflexes.
5.  When  marked  incoordination  of  movements  is  present  and  the
deep  7'eflexes  are  not  abolished,  it  indicates  that  sclerosis  of  the  lateral
columns  probably  co-exists  with  similar  changes  in  Burdach's  columns.
6.  Spasm  is  a  marked  symptom  in  many  diseases  of  the  spinal  cord.
It  commonly  indicates  an  excessive  action  of  the  reflex  motor  centres.
It  is  particularly  common  as  an  acute  symptom  in  spinal  meningitis.  In
chronic  organic  diseases  of  the  cord,  it  assumes  the  form  of  contracture
of  muscles,  especially  if  the  lateral  columns  of  the  cord  are  attacked;  this
condition  becomes  transformed  into  that  of  a  genuine  spasm  when  the
slightest  forms  of  peripheral  impressions  are  experienced,  as  in  delicatel}'
manipulating  the  muscles,  for  example.
The  Organic  Reflexes. —  Tlie  Bladder  and  Rectum. — The  bladder
and  rectum  are  more  or  less  afljeeted,  in  respect  to  the  performance  of
their  functions,  by  those  diseases  of  the  spinal  cord  that  tend  to  impair
or  destroy  the  special  nervous  mechanism  connected  with  them.  Th6
nocturnal  incontinence  of  children,  who  "wet  the  bed"  in  spite  of  all  pre-
cautions against  the  accident,  is  an  evidence  either  of  spasm  of  the
bladder,  excessive  stimulation  of  the  centripetal  nerves  connected  with
the   so-called   "vesical   centres"  of  the   spinal   cord,  or   atony  of  the


THE   OKGANIC  KEFLEXES.
