In animal anatomy, Henry's pocket, more formally known as a cutaneous marginal pouch, is a fold of skin forming an open pouch on the lower posterior part of the

external ear The outer ear, external ear, or auris externa is the external part of the ear, which consists of the auricle (anatomy), auricle (also pinna) and the ear canal. It gathers sound energy and focuses it on the eardrum (tympanic membrane). Structur ...

. The pocket is situated in the approximate location of the

antitragus The antitragus is a feature of mammalian ear anatomy. In humans, it is a small Tubercle (anatomy)#Ears, tubercle on the visible part of the ear, the Auricle (anatomy), auricle. The antitragus is located just above the earlobe and points anatomical ...

in the human ear. It occurs in a number of

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

ian species, including weasels and bats, but is particularly noticeable on the

domestic cat The cat (''Felis catus''), also referred to as the domestic cat or house cat, is a small Domestication, domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have sh ...

, as well as some dog breeds. The pocket is of unknown function, and it is unclear if it has any at all. However, one hypothesis is that it aids in the detection of high-pitched sounds by attenuating lower pitches, especially when the ear is angled, common for a predator when hunting. Since the pocket occurs in a wide variety of mammalian species, it is likely a conserved feature from their common ancestor. The pocket is a common area for

parasite Parasitism is a Symbiosis, close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the Host (biology), host, causing it some harm, and is Adaptation, adapted str ...

s to gather, and should be checked during a veterinary examination.

References

Animal anatomy {{vertebrate-anatomy-stub