it’s taken me however long it’s been between reading homestuck and now to realise that a “stem” (as in what sollux lives on) is also a part of a “brain”
went through the process of forgetting and remembering this a second time, it seems… i’ve been ruminating a lot on what exactly Karkat means when he says “[b]lood skims the voids in your porous cranial plates, as if grazing the hollow of a threshed stem“, which doubles as a reference to a plant stem (of the sort you might cut with a sickle) and to a hive stem (which you might find in an abandoned alternian neighbourhood). but it is also of a piece with his “porous cranial plates” inasmuch as it is another part of his brain through which his blood flows… so if this tract speaks to “the interconnectedness of the characters’ homes and their inner worlds” as I say, and the lawnrings separating Karkat from his neighbours represent the barriers separating him from his otherselves, it should be similarly significant that Sollux lives on what is a giant brain stem (or spine?)… I’m not sure if there’s some “mythology” regarding the brain stem I may be unfamiliar with, though, or if the actual biological function of the brain stem is relevant in some way here
despite a lot of the language used to describe troll brains making them seem quite alien in structure to our own, they do in fact have a brain stem, or at least something very similar:
the reference to a stem being ‘cauterised’ seems like a pretty heavy-handed reference to Sollux’ stem, which has the top blown off it and then ends up in a land of fire. the fact that all this happens as a direct result of Sollux tasting some mind honey and having a psychic reaction is also pretty heavy-handed in indicating that Sollux sustained some brain damage from this overexertion of his powers (which I guess would be retroactively-prefigured by Mituna’s acquired brain damage?)