Thanks David,
It is definitely slimy, but I don't think it is slime mould.
I wonder if it is just palm sap, exuding through damage (eg. palm weevil borings?)
I saw a similar slime issuing in greater volume from the stump of a palm that had been felled.
I guess, there's a good chance, if it is basically sap, that it could be infected by bacteria/fungi/etc. post-effusion (ie. not a primary cause), which could confuse matters.