The synovial membrane is thickened and there is an exudation of serum.
As in croup, part of the exudation or false membrane is often coughed up; sometimes it peels off from the tonsils.
This event also depends upon the quantity and quality of the exudation.
Trees which are attacked by the borer have an exudation of gum about the crown.
The exudation may, as in iritis, be ...