Short PS to Apostrophe

PS In the preceding I've gone along with what is really the 'folk grammar' of the 'possessive'. In reality, the grammar of what is technically the 'genitive' , expressed in English by 'of' and the 's' sound, is wonderfully complex. Possession isn't half of it. We are entitled to use the 's' genitive in many different ways to mean eg a   purpose - 'Children's Literature' means 'for' children; or for classing things 'men's shoes', 'women's shoes' which aren't yet owned by the men or women! and so on. So in actual fact 'possessive' is yet another term we foist on to the unsuspecting (like me at school and college), probably in the hope that we wouldn't question them too closely about it. Remember: obedience is all.