The top panel is taken from p. 18 of Carol A. Himsel's "Rats: A Complete Pet Owner's Manual" (Barrons, 1991). The bottom panel comes to us courtesy of Pete Land, and shows a slightly re-touched section through layer IV of flattened rat barrel cortex, in which the barrels of the straddlers have been airbrushed out to facilitate the labeling of the main rows (A-E). The stain is for cytochrome oxidase, a mitochondrial enzyme.

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