There is a version of Hieland Laddie that I have heard sung here in California that uses the phrases"Donkey Riding" and "Riding on a donkey". I figred without htinking aobut it much that it referred to the donkey engines that came along at the beginning of the age of steam but now that I think of it, that's not a very satisfactory anser. So, I ask, what does it mean. Of course, it will probably turn out to be sexual. THiose guys, they plough the seas all day and then everything turns out to be sexual imagery.