The second and third sentences of the cover caption for "Aphid neurosecretion" [ Science 141, 225 (19 July 1963)] should have read "The nerve passes between a muscle fiber and a fat body cell in the vicinity of the prothoracic spiracle. The axons contain dense neurosecretory granules, neurotubules, and a few mitochondria." The words between prothoracic and neurosecretory were omitted in the published caption.