The unbelievable happened: Last night I rolled the phyllotaxis scarf out on the floor, pulled out the measuring tape and read... 60 inches!!! Wow! Tonight I then did the required 10 rows of garter-stitch-in-the-round and cast off. What joy!
But. Adam didn't spend long in Paradise. Or something. Folding the (finished) scarf I noticed that the end of it - the real end, the one I had just finished - is about half an inch wider than the beginning end. Holy guacamole, what happened!?!?! No extra stitches in this pattern, no, it's just my old fiend GAUGE.
WHY, oh WHY??? Why can I not be a human knitting machine who knits always in the Perfect Immutable Tension??
Coming to think of it, that wouldn't be fun. There'd be no rippin' out of and revisiting (A)FOs, no gauge swatches to assemble into a hideous (or lovely, take your pick) patchwork afghan later on, no collection of 16" and 24" and what-length-have-you knitting needles in 4.00, 4.25, 4.5, 4.75, 5.00 etc. mm... so, basically, no fun.
So, the end of the phyllo scarf will be undone and re-knit on smaller needles. It was knit on 4.25 mm and I think I'll use the 3.5 mm ones in the re-knitting. Given the enormous difference between the two garter stitch segments, I think nothing less will do.