Chicken or the egg?

We enjoyed a fabulous and long walk in the forest above Huntly in Aberdeenshire where we found signs everywhere of previous plantations which had been felled many years ago and which had now been overtaken by a thick mossy carpet. The mossy domes were presumably home to many insects now and the more recent plantings of pine trees were tall and towering above, providing shelter from rain and wind. We walked for about three hours and it was only at the end of the walk that we met anyone else - instead we had been treated to spring birdsong sporadically interrupting the quiet of the old forest. I was intrigued by this huge stone and wondered if it had split first and then the path had been trodden between it, or the other way round. My gut feeling is that it was the former.