Harderian Glands: Porphyrin Metabolism, Behavioral and Endocrine Effects

Harderian glands, first described by Jacob Harder in two species of deer in 1694, are large, intraorbital glands which, with but few exceptions, are found in all land vertebrates. Certainly, their relatively large size, their phylogenetic age, and persistent conservation in all groups as they emerged from an aqueous to an air/land environment lend strong support to the logical deduction that they probably play an important role in the physiological adaptation to terrestrial life. Yet, few b...