Often heared in embryology courses: “Ontongeny recapitulates Phylogeny”.

From a review of an S.J. Gould book:
“The idea that the development of individuals is a progression through adult ancestral forms, epitomised in the saying "ontogeny recapitulates phylogeny", has played an important part in the history of biology. “
At one stage the human embryo has structures resembling gills. Are you listening, WW”

ontogeny
n.
5prec. + 3GENY6 the life cycle of a single organism; biological development of the individual: distinguished from PHYLOGENY: also on[to[gen[e[sis 79n#tb jen4! sis8
on#to[ge[net4ic 73j! net4ik8 or on#to[gen$ic
adj.

phylogeny
n.,
pl. 3nies 5Ger phylogenie, coined (1866) by HAECKEL: see prec. & 3GENY6
1 the lines of descent or evolutionary development of any plant or animal species
2 the origin and evolution of a division, group, or race of animals or plants: distinguished from ONTOGENY
3 the historical development of a nonliving thing, as a group of languages Also phy[lo[gen[e[sis 7fj#lb jen4! sis8
phy#lo[ge[net4ic 73lb j! net4ik8 or phy#lo[gen$ic 73jen4ik8
adj.
phy#lo[ge[net$i[cal[ly
adv.

physiolatry
n. nature worship. physiolater, n. physiolatrous, a.

phytocidal - capable of killing plants

phytopathogen - an agent capable of causing disease in plants

picacho -- Found in many place names. Online Spanish dictionary found no match.

pierian
“A little Learning is a dang'rous Thing;
Drink deep, or taste not the Pierian Spring.”
Alexander Pope

piezo3
5< Gr piezein, to press < IE *pised3, to sit on, press < base *epi3, on + *sed3, SIT6 combining form pressure !piezom

pileiform - shaped like an umbrella

Pilpulist - one who engages in pilpul:
A method of Talmudic study. The word is derived from the verb "pilpel" (lit. "to spice," "to season," and in a metaphorical sense, "to dispute violently

pinaceous
adj.
5PIN(E) 1 + 3ACEOUS6 of the pine family of trees

pinacotheca - a picture gallery

pince-nez pronounced “pance nay”
n.
5Fr < pincer, to pinch + nez, nose6 pl. pince#-nez$ 73naz$; 3na$8 eyeglasses without temples, kept in place by a spring gripping the bridge of the nose

pineal body
a small, grayish, cone-shaped, glandular outgrowth from the brain of all vertebrates that produces the hormone melatonin: in lower vertebrates, often visible as an external median eye

Pinking
<XPAGE=1088Pink"ing, n.
1. The act of piercing or stabbing.
2. The act or method of decorating fabrics or garments with a pinking iron; also, the style of decoration; scallops made with a pinking iron. Pinking iron. (a) An instrument for scalloping the edges of ribbons, flounces, etc. (b) A sword. [Colloq.]

Pinnate, Pinnated
<XPAGE=1088Pin"nate (?), Pin"na*ted (?), a. [L. pinnatus feathered, fr. pinna a feather. See Pin a peg, Pen feather.]
1. (Bot.) Consisting of several leaflets, or separate portions, arranged on each side of a common petiole, as the leaves of a rosebush, a hickory, or an ash. See Abruptly pinnate, and Illust., under Abruptly.
2. (Zoöl.) Having a winglike tuft of long feathers on each side of the neck. Pinnated grouse (Zoöl.), the prairie chicken.
pin[to 7pin4tb8
adj.
5AmSp, spotted < obs. Sp < VL *pinctus: see PINTADO6 marked with patches of white and black or another dark color; piebald or skewbald
n.,

pinto
adj.
5AmSp, spotted < obs. Sp < VL *pinctus: see PINTADO6 marked with patches of white and black or another dark color; piebald or skewbald
n.,

Piolet
third generation peer-to-peer file sharing client for downloading MP3 music files.

pipkin
n.
5? dim. of PIPE, n. 116
1 a small earthenware pot
2 dial. var. of PIGGIN