diff --git a/4-high/gel/source/remote/gel-remote-world.adb b/4-high/gel/source/remote/gel-remote-world.adb
index aba853d..9bf019d 100644
--- a/4-high/gel/source/remote/gel-remote-world.adb
+++ b/4-high/gel/source/remote/gel-remote-world.adb
@@ -163,22 +163,22 @@ is
 
 
 
-   procedure Write (Stream    : not null access ada.Streams.Root_Stream_type'Class;
+   procedure write (Stream    : not null access ada.Streams.Root_Stream_type'Class;
                     the_Event : in              new_graphics_model_Event)
    is
    begin
       openGL.remote_Model.item'Class'Output (Stream,
                                              the_Event.Model.all);
-   end Write;
+   end write;
 
 
 
-   procedure Read (Stream    : not null access ada.Streams.Root_Stream_type'Class;
-                   the_Event : out             new_graphics_model_Event)
+   procedure read (Stream    : not null access ada.Streams.Root_Stream_type'Class;
+                   the_Event :             out new_graphics_model_Event)
    is
    begin
       the_Event.Model := new openGL.remote_Model.item'Class' (openGL.remote_Model.item'Class'Input (Stream));
-   end Read;
+   end read;
 
 
 
diff --git a/4-high/gel/source/remote/gel-remote-world.ads b/4-high/gel/source/remote/gel-remote-world.ads
index ffa6638..ca65dfc 100644
--- a/4-high/gel/source/remote/gel-remote-world.ads
+++ b/4-high/gel/source/remote/gel-remote-world.ads
@@ -39,7 +39,8 @@ is
 
    procedure   register (Self : access Item;   the_Mirror         : in World.view;
                                                Mirror_as_observer : in lace.Observer.view)   is abstract;
-   procedure deregister (Self : access Item;   the_Mirror         : in World.view)           is abstract;
+   procedure deregister (Self : access Item;   the_Mirror         : in World.view;
+                                               Mirror_as_observer : in lace.Observer.view)   is abstract;
 
 
 
@@ -71,8 +72,8 @@ is
       end record;
 
 
-   procedure Write (Stream : not null access ada.Streams.Root_Stream_type'Class;   the_Event : in  new_graphics_model_Event);
-   procedure Read  (Stream : not null access ada.Streams.Root_Stream_type'Class;   the_Event : out new_graphics_model_Event);
+   procedure write (Stream : not null access ada.Streams.Root_Stream_type'Class;   the_Event : in     new_graphics_model_Event);
+   procedure read  (Stream : not null access ada.Streams.Root_Stream_type'Class;   the_Event :    out new_graphics_model_Event);
 
    for new_graphics_model_Event'write use write;
    for new_graphics_model_Event'read  use read;
diff --git a/4-high/gel/source/world/gel-world-client.adb b/4-high/gel/source/world/gel-world-client.adb
index 2f7fbcc..f4dd3fb 100644
--- a/4-high/gel/source/world/gel-world-client.adb
+++ b/4-high/gel/source/world/gel-world-client.adb
@@ -419,8 +419,8 @@ is
       --
       the_new_graphics_model_Response.World := Self.all'Access;
 
-      Self.add (the_new_graphics_model_Response'Access,
-                to_Kind (remote.World.new_graphics_model_Event'Tag),
+      Self.add (the_Response => the_new_graphics_model_Response'Access,
+                to_Kind      => to_Kind (remote.World.new_graphics_model_Event'Tag),
                 from_Subject => of_World.Name);
 
       --  New physics model response.
diff --git a/4-high/gel/source/world/gel-world-server.adb b/4-high/gel/source/world/gel-world-server.adb
index aa7a224..3b1d715 100644
--- a/4-high/gel/source/world/gel-world-server.adb
+++ b/4-high/gel/source/world/gel-world-server.adb
@@ -282,20 +282,25 @@ is
    begin
       Self.Clients.append (the_Mirror);
 
-      Self.register (Mirror_as_observer,  to_Kind (remote.World.        new_graphics_model_Event'Tag));
-      Self.register (Mirror_as_observer,  to_Kind (remote.World.         new_physics_model_Event'Tag));
-      --  Self.register (Mirror_as_observer,  to_Kind (gel.events.                  new_sprite_Event'Tag));     -- TODO: Rid.
-      Self.register (Mirror_as_observer,  to_Kind (gel.events.new_sprite_Event'Tag));
-      Self.register (Mirror_as_observer,  to_Kind (gel.events.rid_sprite_Event'Tag));
+      Self.register (Mirror_as_observer, to_Kind (remote.World.new_graphics_model_Event'Tag));
+      Self.register (Mirror_as_observer, to_Kind (remote.World. new_physics_model_Event'Tag));
+      Self.register (Mirror_as_observer, to_Kind (gel.events  .new_sprite_Event        'Tag));
+      Self.register (Mirror_as_observer, to_Kind (gel.events  .rid_sprite_Event        'Tag));
    end register;
 
 
 
    overriding
-   procedure deregister (Self : access Item;   the_Mirror : in remote.World.view)
+   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view;
+                                               Mirror_as_observer : in lace.Observer.view)
    is
    begin
       Self.Clients.delete (Self.Clients.find_Index (the_Mirror));
+
+      Self.deregister (Mirror_as_observer, to_Kind (remote.World.new_graphics_model_Event'Tag));
+      Self.deregister (Mirror_as_observer, to_Kind (remote.World. new_physics_model_Event'Tag));
+      Self.deregister (Mirror_as_observer, to_Kind (gel.events  .new_sprite_Event        'Tag));
+      Self.deregister (Mirror_as_observer, to_Kind (gel.events  .rid_sprite_Event        'Tag));
    end deregister;
 
 
diff --git a/4-high/gel/source/world/gel-world-server.ads b/4-high/gel/source/world/gel-world-server.ads
index 79b5d06..5173b4c 100644
--- a/4-high/gel/source/world/gel-world-server.ads
+++ b/4-high/gel/source/world/gel-world-server.ads
@@ -51,7 +51,8 @@ is
    procedure   register (Self : access Item;   the_Mirror         : in remote.World.view;
                                                Mirror_as_observer : in lace.Observer.view);
    overriding
-   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view);
+   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view;
+                                               Mirror_as_observer : in lace.Observer.view);
 
    overriding
    procedure evolve     (Self : in out Item);
diff --git a/4-high/gel/source/world/gel-world.adb b/4-high/gel/source/world/gel-world.adb
index 63016a4..20ebce5 100644
--- a/4-high/gel/source/world/gel-world.adb
+++ b/4-high/gel/source/world/gel-world.adb
@@ -883,7 +883,8 @@ is
    procedure   register (Self : access Item;   the_Mirror         : in remote.World.view;
                                                Mirror_as_observer : in lace.Observer.view) is null;
    overriding
-   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view) is null;
+   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view;
+                                               Mirror_as_observer : in lace.Observer.view) is null;
 
    overriding
    procedure motion_Updates_are (Self : in Item;   seq_Id : in remote.World.sequence_Id;
diff --git a/4-high/gel/source/world/gel-world.ads b/4-high/gel/source/world/gel-world.ads
index 685421e..41ca74a 100644
--- a/4-high/gel/source/world/gel-world.ads
+++ b/4-high/gel/source/world/gel-world.ads
@@ -251,7 +251,8 @@ is
    procedure   register (Self : access Item;   the_Mirror         : in remote.World.view;
                                                Mirror_as_observer : in lace.Observer.view);
    overriding
-   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view);
+   procedure deregister (Self : access Item;   the_Mirror         : in remote.World.view;
+                                               Mirror_as_observer : in lace.Observer.view);
 
    overriding
    procedure motion_Updates_are (Self : in Item;   seq_Id : in remote.World.sequence_Id;