I  have  stated  that  the  hyaloid  membrane  may  become
inflamed  and  absorbed,  that  its  secretion  maybe  increased,
and  that  hsmorrhage  may  take  place  into  its  cells,  and  I
may  mention  that  it  may  also  secrete  pus  and  lymph,  and
that  it  may  become  the  seat  of  ossification.^  Chronic
inflammation  of  the  septa  of  the  hyaloid  membrane  may
thicken  them  and  render  them  opaque,  but  its  more
usual  effect  I  have  already  stated  when  treating  of
glaucoma.
We  must  view  the  pathology  of  the  vitreous  humor
as  that  of  every  other  part,  in  connexion  with  its  ana-
tomy. The  capsule  of  the  vitreous  humor  is  a  serous
membrane,  and  is  liable  to  all  those  diseases  to  which
other  serous  membranes  are  exposed.  If  these  changes
are  not  mentioned  or  described  until  a  comparatively
recent  period,  we  may  be  assured  that  the  omission  arose
from  the  prevalence  of  the  singular  and  contracted  notions


*  Cases  of  this  latter  description  are  related  by  Moroaoni,  Lob-
stein,  Baillie,  Bebb,  Scabpa,  Wabdrop,  Warren,  and  Kuhn.
24

which  were  fonnerly  entertainecl  respecting  the  pathology
of  the  eye,  and  to  the  confinement  of  the  management  ol
its  maladies  to  a  distinct,  and  generally  very  ignorant,
class  of  persons,  termed  **  oculists.**  It  would  seem  firom
the  expressed  opinions  of  some  writers  that  the  organ  of
vision  was  composed  entirely  of  '^  sui-generis  textures,**
which  were  by  no  means  obnoxious  to  those  morbific
agents  which  we  acknowledge  to  originate  disease  in
other  parts  consisting  of  simUar  anatomical  structures—
that  they  were,  in  fact,  incapable  of  undergoing  many  of
those  diseased  changes  to  which  the  same  textures  when
forming  other  organs,  are  known  to  be  obnoxious.
CHAPTER  XIII.
DISEASES    OF    THE   CRYSTALLINE    LENS   AND   ITS

CAPSULE.
