Fig. 2. Incident light micrographs of a portion of the anterior cardiac nerve (acn) and stomatogastric nerve (stn). (A) Incident light micrograph of the acn. This image, taken approximately 400 µm from the junction of the acn and the stn (see Fig. 1), shows numerous iridescent bluish-white profiles. These profiles appear superficially located and cover an approximately 1000 µm stretch of the nerve. (B) Incident light micrograph of the stn. In contrast to the acn, no iridescent profiles are seen in this nerve or in any other nerves (other than the acns) or ganglia that comprise the stomatogastric nervous system. Scale bar, 100 µm.