APPENDIX I 



Suppressor, a gene one of whose allelomorphs renders indetectable the 



difFcrcncc determined by the allelomorphs of another gene. 



V. Epistasy. 

 Synapsis (Syndesis), chromosome pairing at pachytene and zygotene. 



V. Asynapsis. Moore 1895. 

 Syndiploidy, doubhng, the fusion of sister nuclei to give a doubled 



cliromosome number, particularly in the divisions immediately 



preceeding meiosis. Strasburger 1907. 

 Syndrome, a group of symptoms characteristic of the same infection 



or abnormal genetic condition, but not necessarily all appearing 



together. 

 Syngamy, fusion of gametes. 

 Synoecy, the condition in which male and female gametes are produced 



by the same haploid or diploid individual. Includes Monoecy and 



Hermaphroditism. Correns 1928. 



t, the ratio of an observed deviation to its estimated standard deviation. 



Telegony, an effect of a previous sire on later progeny of the same dam 

 by another sire. Stockbreeder's myth. 



Telocentric, of a chromosome or a chromatid having a terminal 

 centromere. A condition arising by Misdivision or by X-Ray 

 Breakage. Darlington 1939. 



Telosyn apsis, v. Parasynapsis. 



Telophase, the stage of mitosis and meiosis during which the chromo- 

 somes re-form a nucleus. 



Terminal Afhnity, the property by which chromosomes are held 

 together end to end from Diplotene till first Metaphase of Meiosis 

 (by a Terminal Chiasma) or are brought together in this way at 

 Metaphase. Darlington 1932. 



Terminal Cihasma, v. Chiasma. 



Terminalization, expansion of the association of the two pairs of 

 chromatids on one side of a chiasma at the expense of that on the 

 other side. So called because the resulting "movement" of the 

 chiasma is towards the ends of the chromosomes. Darlington 

 1929. 



Test Cross, a cross of a double or multiple heterozygote to the cor- 

 responding double or multiple recessive. Used to estimate linkage 

 relationships or behaviour. Bridges 1934. 



Tetrad, quartet of cells formed by meiosis in a mother cell. 



Tetraploid, v. Polyploid. Nemec 1910. 



Tetrasomic, v. Polysomic. 



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