APPENDIX III 

 GLOSSARY 



If men shal telle proprely a thing 

 The word mot cosin be to the werking. 



Chaucer, Maunciple's Tale. 



Terms not used in the text are enclosed in brackets. The usages given 

 are those adopted in this book and are not always the original ones, 

 since usage necessarily changes. For the sources of many of these the 

 author is indebted to Wilson (1928), Rosenberg (1930). Carothers (1931)* 

 and a number of correspondents. 



Acentric, of the whole or part of a chromatid or chromosome lacking a centro- 

 mere. 



Allelomorph, one of two dissimilar factors which on account of their corre- 

 sponding position in corresponding chromosomes are subject to alternative 

 (mendelian) inheritance in a diploid. Bateson, 1902. 



Allopolyploid, a polyploid whose chromosomes do not usually form multi- 

 valents at meiosis but form bivalents as far as their homologies allow 

 them, e.g., a. tetraploid with 2X bivalents or a triploid with x bivalents 

 and X univalents {cf. Autopolyploid, v, Text). Kihara and Ono, 1926. 



Allosyndesis, the pairing in a polyploid of chromosomes derived from opposite 

 parents ; particularly as opposed to autosyndesis, in a hybrid between 

 allopolyploids. Ljungdahl, 1922. 



Alternation of Generations, the occurrence of two series of nuclear divisions 

 in the life cycle, a haploid and a diploid. 



Ameiosis, the occurrence of one division of the nucleus instead of the two of a 

 normal meiosis, giving non-reduction of the mother-cell, 



Amitosis, the division of a nucleus without separation of daughter chromo- 

 somes. Flemming, 1882. 



[Amphidiploid], allotetraploid, v. allopolyploid. 



Amphimixis, the bringing together ot elements from two gametes in fertilisa- 

 tion (as opposed to apomixis). Weismann, 1891. 



Anaphase, the stage at which daughter chromosomes move apart in a nuclear 

 division. Strashurger, 1884. 



Androgenesis, male parthenogenesis, q.v. 



Aneuploid, having the different chromosomes of the set present in different 

 numbers, through purely numerical aberration — therefore an unbalanced 

 polyploid. Tdckholm, 1922. 



[Anisogamy, heterogamy, q.v.'] 



Apogamy, apomixis involving the replacement of the gametes by unspecialised 

 cells which do not fuse. De Bary, 1878 ; Winkler, 1908. 



Apomixis, the occurrence of the external form of sexual reproduction with the 

 omission of fertilisation and usually meiosis as well (as opposed to amphi- 

 mixis). Winkler, 1908. 



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