While not at all immediately apparent, Jasper John's Perilous Night was modeled after Grünewald's Isenheim Altarpiece. Most specifically, the shapes sketched into the encaustic on the left side. But the use of the hands has a more obvious connection, as well as the block-framing shapes, only in this case, two dimensional and set into place, not capable of opening outward like an altarpiece. While I don't know if Tarn was thinking about John's work when writing Ins and Outs of the Forest Rivers, a resemblence in the themes exists: the blocking of the viewer's vision, the forced compartments, the limited access to the totality of the scene, all of which Tarn is concerned has happened to our vision of life. Tarn's poetry also making direct reference to hands and feet, which are aspects of the crucifixion, and also re-emphasize the notition of the 'particular' and the relation to the 'whole'. Its through our hands, our bodies, that we relate directly with life, this being a much different relation than through ideologies. From Tarn's poem 'Hands':

...............On the floor a closed box. Can it contain
persuasive numbers of human hands, cut from their too
possessive bodies? Is it natural that a body should need
its hands? Not in the present circumstance, not in these
politics. Evanescent, rapturous clouds dream way above
the mortal scene while soldiers move forth under orders,
sliding round walls, darting from post to post, kicking
doors in with their remaining feet. A dark within there,
darkness of poverty devoid of fire or even lamps, a dark
lost to pretence. Asleep. Three to kill, one to rape.