Knight — 112 — Dictionary 



Pathotype. — A group of individuals all exhibiting the same 

 pathological condition. 



Patriclinic, Patriclinous, — Patroclinous, q.v. 0pp. Matro- 

 clinous. 



Patroclinal Inheritance. — Inheritance in which the offspring 

 resembles the father more closely than the mother. 



Patroclinic. — Resembling the father more closely than the 

 mother. 



Patroclinous. — Patroclinic, q.v. 



Patrogenesis. — The production of a 'zygote' whose chromatin 

 is derived solely from the male gamete. 



Patrogony. — Modificational adaptation during embryo or 

 larval development. 



Patromorphic. — Similar in appearance to the male parent. 



Pedigree, — A record or history of the ancestry of an indi- 

 vidual, strain or variety. 



Peloria, Pelory. — Reversion, on the part of an individual, to 

 the production of regular flowers, when the species typiocally 

 has asymmetrical flowers. Adj. Peloric. 



Penetrance. — The percentage frequency with which a gene 

 produces any effect at all. See Complete Penetrance; Pene- 

 trance, Reduced; Incomplete Penetrance, cj. Expressivity. 



Penetrance, Reduced. — A reduction in the number of indi- 

 viduals in any one phenotype though the number in the corre- 

 sponding genotype is not reduced, i.e. the particular gene or 

 genes involved, though present, are not always manifest. 



Penis. — The intromissive copulatory organ of the male 

 mammal. 



Pentagynous. — Of a flower: having five styles. 



Pentandrous. — Of a flower : having five stamens. 



Pentaploid. — Having five haploid sets of chromosomes in the 

 somatic cells. 



Perfect. — Of a flower : possessing both stamens and pistils, 

 i.e. hermaphroditic. 



Perforatorium. — A specialised pointed portion of the achro- 

 some, q.v. 



Perianth. — The calyx and corolla collectively. 



Pericarp. — The wall of a fruit, when derived from the ovary 

 wall, consisting of three layers: exocarp, mesocarp and endo- 

 carp. 



Pericentric Inversion. — An inversion which involves the 

 centromere. 



Periclinal Chimaera. — A plant made up of two genetically 



