POGO´NIUM, _n._; pl. _pogonia_. Web or vanes of a feather. (147.)
_Pogonium externum_, outer web (farthest from middle line of the body).
_Pogonium internum_, inner web. See PLUMA.
POL´LEX, _n._ Thumb. The joint which bears the alula is so called,
though it is homologous with the index or second finger. _Spina
pollicaris_, or _Tuberculum pollicare_, the horny spur on the wing of
some birds.
POLYG´AMOUS, _a._ Mating with more than one female, like the domestic
cock.
POLYMOR´PHIC, _n._ Of many forms; consisting of, or containing, several
different types of structure: as, a _polymorphic group_.
POLYMY´OID, _a._ Having numerous syringeal muscles; noting a group
equivalent to _Oscines_.
POLYNO´MIAL, _n._ or _a._ Name of more than two words. Consisting of
several words. The _polynomial_ nomenclature is obsolete.
POLYTO´KOUS, _a._ Multiparous; producing many young.
PONS, _n._ Bridge. Certain parts of the brain.
POPLITE´AL, _a._ Pertaining to the back of the knee.
POR´TAL CIRCULA´TION. Passage of blood from the capillaries of one organ
to those of another, as is conspicuous in certain of the digestive
viscera.
POSTAX´IAL, _a._ Situate on the external or posterior (ulnar or fibular)
side of a limb.
POSTE´RIOR PORTION. (8.) See URÆUM.
POSTERIOR TOE. (125.) The hind-toe, or that one directed backward, is
generally the hallux; often also the fourth or outer; rarely the second
or inner. The hallux is generally meant by _posterior toe_.
POSTOR´BITAL, _a._ Situate behind the eye.
POW´DER-DOWN FEATH´ERS, _n. pl._ Peculiar imperfect feathers, in a
matted patch, which grow continually, and as constantly break down, with
a scurfy exfoliation, and pervaded with a greasy substance; they are
especially conspicuous in the heron tribe, but are also found elsewhere.
PRÆAX´IAL, _a._ Situate on the internal or anterior (radial or tibial)
side of a limb.
PRÆCO´CES, _n. pl._ An obsolete group of birds, able to run about and
feed themselves at birth.
PRÆCO´CIAL, _n._ Belonging to the _Præcoces_; having the nature of
_Præcoces_.
PRÆPEC´TUS, _n._ Fore-breast; region of the craw. Not well distinguished
from _jugulum_.
PREMAX´ILLARY (_bone_), _a._ The foremost and principal bone of the
upper jaw. _Intermaxillary_ is synonymous.
PREP´UCE, _n._ Foreskin. The homologous structure occurs in some birds.
_Preputial_, pertaining to the foreskin.