APPENDIX I 



Anisogeny, the property of having different inheritance in reciprocal 



crosses. Now known to be due to Cytoplasmic hiheritance, Complex 



Heterozygosity, or lack of Balance. Bateson 1925. 

 Antimorph, v. Amorph. 

 Apogamy, Apomixis in which the reproductive function of the gametes 



is taken over by unspeciahzed cells. Dc Bary 1878. 

 Apomixis, the occurrence of the external form of sexual reproduction 



with the omission of fertilization and usually of meiosis as well. As 



opposed to Amphimixis. Subdivided into Natural, which may be 



Facultative or Obligatory, and Artihcial. In animals it always 



takes the form of Parthenogenesis. Winkler 1908. 

 Apospory, Apomixis in wliich the reproductive function of the spores 



is taken over by unspecialized cells. Bower 1887. 

 Asexual Reproduction, v. Reproduction. 

 AsYNAPSis, non-pairing of chromosomes at pachytene, or a failure of 



chiasmata supposedly derived from non-pairing. Beadle 193 1. 

 Atavism, resemblance to more remote ancestors, rather than to parents. 



Now understood as due to Segregation, Recombination, incomplete 



Penetrance or Mutation. 

 Attachment, v. Spindle Attachment and Attached X Chromosomes. 

 Autogamy, Self-Fertilization, especially in Infusoria. 

 Auto-Orientation, v. Orientation. 

 Autopolyploid, a polyploid with identical sets of chromosomes, or 



approaching this condition. Kihara and Ono 1926. 

 Autosome, a chromosome whose segregation from its partner at meiosis 



does not normally affect the determination of sex. Montgomery 1906. 

 AuTOSYNDESis. I. The pairing in a cross between two polyploids of 



chromosomes derived from the same parent. 

 2. Pairing in an allopolyploid between chromosomes derived from 



the same ultimate diploid ancestor. As opposed to Allosyndesis. 



Ljungdahl 1924. 

 AzYGOTE, individual arising by haploid Parthenogenesis. Whiting and 



Benhert 1934. 



Backcross, the cross of a hybrid with one of its parents or a genetically 

 equivalent cross. N.B. not to include Test-Cross. 



ACTERIOPHAGE, a Virus acting on bacteria. 



ALANCE, a fit adjustment of the genetic components of an individual. 



Inter-Chromosome Balance, the condition in which whole chromo- 

 somes are adjusted in proportions that give satisfactory development 

 of the organism. 



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