I copied this. I'm wondering if this is a misprint as I've never heard of this before. I've always seen it the other way around.
"Usually, the tip end of traditional arrows is made from what was the top end of the sapling as it was growing. This is because the top of the plant is more likely to grow with bends in it than is the base. Over time, straightened sections of arrow-shafts can warp back towards the sapling's original form. If warp has to occur, it is better for it to occur near the tip where it can easily be straightened out again, rather than at the base, where it will be covered by the feathers and difficult to restraighten."