CAROTID  BODIES These are two small bodies situated, one on each

side, between the origins of the external and internal carotid arteries . Microscopically they are divided into nodules or cell balls by connective tissue, and these closely resemble the structure of the parathyroids, but are without any thymic tissue . The blood-vessels in their interior are extremely large and numerous . The modern view of their development is that they are part of the sympathetic system, and the reaction of their cells to chromium salts bears this out . (See Kohn, Archiv f. mikr . Anat. lxx., 1907.) In the Anura there is a rete or network into which the carotid artery breaks up in the position of the carotid body, and this has an important effect on the course of the circulation . It is probable, however, that this structure has nothing to do with the carotid body of Marmalia .