Metaplasm: secondary or differentiated plasm.
Protoplasm: primitive or undifferentiated plasm.

PLASSON: the simplest form of plasm.

PLASTIDULES: small particles of plasm.

POLYSPERMISM: the penetration of more than one sperm-cell into the ovum.

PRO- or PROT: (in compounds) the earlier form (opposed to META); hence:--
Prochorion: the first form of the chorion.
Progaster: the first or primitive stomach.
Pronephridia: the earlier form of the kidneys.
Prorenal: the earlier form of the kidneys.
Prostoma: the first or primitive mouth.
Protists: the earliest or unicellular organisms.
Provertebrae: the earliest phase of the vertebrae.
Protophyta: the primitive or unicellular plants.
Protoplasm: undifferentiated plasm.
Protozoa: the primitive or unicellular animals.

RENAL: pertaining to the kidneys (renes).

SCATULATION: packing or boxing-up (scatula = a box).

SCLEROTOMES: segments into which the primitive skeleton falls.

SOMA: the body; hence:--
Cytosoma: the body of the cell (cytos).
Episoma: the upper or back-half of the embryonic body.