Phenotype — 115 — Pleiomery 



Planogamic. — With motile gametes. 



Planosome. — A supernumerary chromosome resulting from 

 non-disjunction of a bivalent in meiosis. 



Plasma Membrane. — A film which surrounds the cytoplasm. 



Plasmagel. — The more viscous portion of cytoplasm in con- 

 tradistinction to the plasmasol, q.v. 



Plasmagenes. — Determinants, or units of heredity, located in 

 the cytoplasm, cf. Plasmon. 



Plasmasol. — The more fluid portion of the cytoplasm in 

 contradistinction to the plasmagel, q.v. This commonly lies 

 within the denser plasmagel. 



Plasmodesms. — Fine protoplasmic strands connecting neigh- 

 bouring cells. 



Plasmogamy. — Cytoplasmic fusion. 



Plasmogony. — Abiogenesis, q.v. 



Plasmon. — The system of hereditary units thought by some 

 to exist in the cytoplasm, as opposed to the system of genes 

 in the chromosomes, cf. Plasmagenes. 



Plasmosome. — A darkly staining body occurring in the nuclei 

 of most cells ; nucleolus. 



Plasome. — Biophore, q.v. 



Plasticity. — The potentiality for further evolution. 



Plasticity, Modificational. — The capacity of an organism, 

 species, or group of organisms, to adapt itself to changes 

 in the environment. See Stenoplastic and Euryplastic. 



Plastid. — Any minute dense protoplasmic cell-inclusion. 



Plastid System of Heredity. — The "corpuscular" system of 

 heredity in which units of heredity, or determinants, are 

 carried in the plastids. cf. Nuclear System and Cytoplasmic 

 System. 



Plastidome. — A collective term for all the plastids in a single 

 cell. 



Plastochondria. — Mitochondria. 



Plastocont. — A rod-like or thread-like chondriosome ; chond- 

 riocont. 



Plastogamy. — Cytoplasmic fusion. 



Plastogenes. — Determinants, or units of heredity, located 

 in the plastids. 



Plastomere. — The part of a spermatozoon in which the 

 chondriosomes occur. 



Plastosome. — A self-propagating body with low refraction 

 occurring in the cytoplasm; chondriosome. 



Pleiomery. — The state of having more than the normal num- 

 ber of parts. Adj. Pleiomeric. cf. Meiomery. 



