The leaves of <i>Adiantum capillus-veneris</i> are six to twenty inches long and three to each inches wide. The leaflets are nearly a half inch wide and are irregularly lobed.

Pinna of Adiantum Capillus-Veneris

The leaves of Adiantum capillus-veneris are six to twenty inches long and three to each inches wide.…

The leaves of <i>Adiantum continuum</i> are twelve to eighteen inches long and grow on stout, black stalks. This fern is found from Mexico to Brazil.

Pinna of Adiantum Concinnum

The leaves of Adiantum continuum are twelve to eighteen inches long and grow on stout, black stalks.…

"Diagram showing the ear and related parts in a young cat. P., Pinna; Sq., squamosal: E.A.M., external auditory meatus; T., tympanum; M., malleus; I., incus; St., stapes abutting onforamen ovale; B., bulla of tympanic bone; Se., a septum in the bulla; E.T., eustachian tube leading from the tymmpanic cavity to the back of the mouth; B.O., basi-occipital; C., cochlea; S., sacculus; U., utriculus; D.E., ductus endolymphaticus; N., auditory nerve; S.C., semi-circular canal; PE., periotic bone." -Thomson, 1916

Cat Ear

"Diagram showing the ear and related parts in a young cat. P., Pinna; Sq., squamosal: E.A.M., external…

A slightly-toothed fern with fronds ranging between 1 foot and 2 feet in length. It is a long and slender plant, commonly found in tropical America.

Pteris Denticulata

A slightly-toothed fern with fronds ranging between 1 foot and 2 feet in length. It is a long and slender…

The external ear consists of an expanded portion named pinna or auricula, and the auditory canal or meatus. Shown is the right pinna viewed from without.

External Ear

The external ear consists of an expanded portion named pinna or auricula, and the auditory canal or…

"External Ear, or Pinna. 1, helix; 2, fossa of antihelix, or fossa triangularis; 3, fossa of helix, or fossa scaphoidea; 4, antihelix; 5, 5, concha; 6, antitragus; 7, lobule; 8, tragus." -Whitney, 1911

External Ear

"External Ear, or Pinna. 1, helix; 2, fossa of antihelix, or fossa triangularis; 3, fossa of helix,…

Structure of the ear.

Structure of the Ear

Structure of the ear.

"Top, lateral pinna from a leaf of Marattia jraxinea. Below at left, synangium of same. At right, corss-section of the synangium." -Gager, 1916

Marratia Fern

"Top, lateral pinna from a leaf of Marattia jraxinea. Below at left, synangium of same. At right, corss-section…

The common name of hymenophyllum is filmy fern. The unilaterale variety has dark green, rigid fronds. This fern is native to Great Britain.

Habit and Detached Pinna with Involucre of Hymenophyllum Unilaterale

The common name of hymenophyllum is filmy fern. The unilaterale variety has dark green, rigid fronds.…

"Pinnate.--Term applied to a leaf when cut into many parallel segments, like the rose." -Newman, 1850

Pinnate

"Pinnate.--Term applied to a leaf when cut into many parallel segments, like the rose." -Newman, 1850

"A. Colony of Pennatula phosphorea from the metarachidial aspect. p, The peduncle. B, Section of the rachis bearing a single pinna. a, Axis; b, metarachidial; c, prorachidial; d, pararachidial stem canals." &mdash; The Encyclopedia Britannica, 1910

Pennatula Phosphorea

"A. Colony of Pennatula phosphorea from the metarachidial aspect. p, The peduncle. B, Section of the…

"The outer ear consists of a plate of gristle, shaped somewhat like a shell, known as the pinna, or auricle, and of a tube about an inch long, called the auditory canal." &mdash; Blaisedell, 1904

Pinna

"The outer ear consists of a plate of gristle, shaped somewhat like a shell, known as the pinna, or…

Inner surface of cartilage of pinna.

Inner Surface of Pinna Cartilage

Inner surface of cartilage of pinna.

Outer surface of cartilage of pinna.

Outer Surface of Pinna Cartilage

Outer surface of cartilage of pinna.

The cartilage of the right pinna, isolated, with muscles, viewed from the inside.

Cartilage of the Pinna

The cartilage of the right pinna, isolated, with muscles, viewed from the inside.

View of outer surface of left pinna.

Outer Surface of Pinna

View of outer surface of left pinna.