APPENDIX I 



Inheritance (continued) 



Cytoplasmic Inheritance, the occurrence of heritable differences 

 determined by the transmission of the cytoplasm. Detected by the 

 difference in contribution of the male and female parents or by the 

 absence of segregation referable to chromosome movement, v. 

 Plasmagene. 



Delayed Inheritance, that whereby each generation manifests, with 

 regard to particular characters, the genotype of the female parent. 

 Boycott et. al. 1923. 



Maternal Inheritance, the occurrence of heritable differences, 

 referable to materials transmitted by way of the egg, but not by 

 way of the sperm, owing to Cytoplasmic Inheritance, v. Delayed 

 Inheritance. 



Matrilinear Inheritance, of determinants (in the cytoplasm) which 

 are transmitted only in the female line. 



Matroclinal Inheritance, where the offspring resembles the mother 

 more closely than the father. As opposed to Patroclinal Inheri- 

 tance. 



Mendelian Inheritance, obeying Mendel's laws. Particulate as opposed 

 to Blending. 



Plastid Inheritance, determined by Plastogenes. 



Quantitative Inheritance, of characters where the variation is con- 

 tinuous. V. Polygenes. 



Unilateral Inheritance, the resemblance of offspring to the parent 

 of the same sex owing to sex linkage in the Y chromosome. 

 V. Linkage. Winge 1927. 

 Interaction of Genes, the process by which one gene-difference affects 



the expression of another gene-difference. 

 Interchange, an exchange of non-homologous terminal segments of 

 chromosomes. May be symmetrical or asymmetrical (giving acentric 

 and dicentric products) with respect to the centromere. The term 

 "segmental interchange" was used by Belling to include crossing- 

 over, but the two are conveniently distinguished, v. Structural 

 Change. Belling 1927. 

 Interference, the property by which one cross-over interferes with the 

 the occurrence of another cross-over in its neighbourhood. 



1. Genetical Interference, as measured from the frequencies of 

 recombinations in the progeny of a multiple Heterozygote. v. 

 Coincidence, Coefficient of. Midler 1916. 



2. Cytological Interference, as measured by the variance of the 

 frequency distribution of Chiasmata in a bivalent. Haldane 193 1. 



399 



