APPENDIX I 



Progeny Test, the method of assessing the genetic character of an 

 individual by the performance of its progeny. First used systematically 

 by Mendel. 



Pro-Metaphase, stage between the dissolution of the nuclear membrane, 

 and the congression of the chromosomes on the Metaphase Plate, 

 especially at the first meiotic division. Lawrence 193 1. 



Prophase, the stage in mitosis or meiosis from the appearance of the 

 chromosomes to Metaphase. Strashiirger 1884. 



Propositus, the individual through whom a pedigree is ascertained. 



Prothallium (Prothallus), the gametophyte in the Pteridophyta. 



Protoplasm, the aggregate of self-propagating structures and materials 

 within the Cell. Purkinje 1840. 



Protoplast, the protoplasm of one cell. Hanstein 1880. 



Proximal, of a part of a chromosome arm which is nearer to the centro- 

 mere than another (Distal) part. 



Pseudo-Compatibility, the occurrence under exceptional conditions of 

 fertilization such as would normally be excluded by Incompatibility. 



Pseudogamy, apomictic development of an embryo from a female 

 gamete or cell under the stimulus of male gametes but without 

 fertilization. Focke 1881. 



Pure Line. i. The descendants obtained from self-fertilization of a single 

 homozygous pzrent. Johannsen 1903. 

 2. In modem usage, an inbred homogenic strain. 



Quadrivalent, v. Univalent. 

 QuADRUPLEX, V. NulHplex. 



Race, a genetically, and as a rule geographically, distinct Mating Group 

 within a Species. 



Random Mating, the situation within a population in which, subject 

 to known restrictions of determinable effect, such as Dioecy, Incom- 

 patibility and intra-uterine copulation, each individual has an equal 

 chance of mating with any individual, including itself, v. Panmixis. 



Randomization, the process of arriving at a random combination of 

 types of event. 



Randomized Block, an experimental design involving one Restraint. 



Randomness, that combination of types of event in which the dis- 

 tribution in classes of one has no causal relation with the distribution 

 in classes of the others, i.e. arrived at by chance without discrimina- 

 tion or choice. 



Recapitulation, Theory of, that the developmental history of organisms 

 repeats their evolutionary history. Kielmeyer 1793 • 



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