You are right, docrum. It's an anagram of 'spawning'. I'm also stuck on last one: 17d 'Bread - Croatian money?' I've put Split ten, but not sure it's right and can't parse it.
Of course! Many thanks. I did google 'Split' + 'bread', but this didn't come up. Many years ago, we used to buy 'tin' loaves (meaning 'unsliced'), but I've not heard this expression before.