DEFICIENCY HETEROZYGOTES i6i 



{h) Triploids. 



ZeaMays (lo) x Euchlcena perennis (20), 2'" + 10" -f 8r Longley, 1924. 

 Artemisia nitida {^x = 2y), 9-13". Chiarugi, 1926; cf. Rosenberg on 



Hieracium, 191 7, and Ch. XI. 

 ^gilops ovata (14) x ^S. caudata (7), 7-10". Bleier, 1928. 

 Mgilops speltoides (7) x Triticum turgidum (14). Jenkins, 1929. 



Bivalents . . . 4 5 6 7 8 9 10 



Frequency . . . i 5 9 71 15 i i 



Avena barbata (14) x A. slrigosa, 9" + 3^ Nishiyama, 1929. (N.B. 



lateral chiasma) . 

 Triticum csgilopoides (7) x T. dicoccum (14), iiv _[_ jiii _}_ ^11 _}, 6i_ 



Kihara and Nishiyama, 1930. 

 Fragaria bracteata vesca (14) X -F. collina (7), 10", etc. Yarnell, 193 1 b. 

 CEnothera pycnocarpa {-^x = 21) (see text). Catcheside, 1931. 

 Campanula persicifolia {^x = 24), iiv -|- ^in -|- 311 _j_ 21. Gairdner and 



D., 1931. 

 [Festuca pratensis (7) x Lolium perenne (7)] X L. perenne {^x = 21), 



31", 6", etc. Peto, 1934. 

 Potentilla chinensis (7) X P. nipponica (14). Araki, 1932. 

 Triticum dicoccum (14) X T. monococcum (7). Mather, 1935. 

 Narcissus Tazetta {^x — 30). Nagao, 1933. 

 Petunia {ix X ^x, x — j). Matsuda, 1935. 



(c) Tetraploids. 



Tradescantia virginiana {x = 6) 

 Campanula persicifolia {x = 8) 

 Aucuba japonica [x = d>) 

 Rosa relicta (x = 7) 

 CEnothera Lamarckiana {x = 7) 

 Anthoxanthum odoratum {x = 5) 



Setcreasia brevifoUa [^x = 24) 

 CEnothera biennis gigas {x = 7) 



{d) Hexaploid. 



Rumex acetosella [x = 7) (associa- 

 tion of 8) . . . . . Kihara, 1927. 



D., 1929 c. 



Gairdner and D., 1931. 



Meurman, 1929 b. 



Erlanson, 193 1 b. 



Hcikansson, 1927. 



Kattermann, 193 1 ; cf. Avdulov, 



1931- 

 Richardson, 1935. 

 Seitz, 1935. 



(vii) Unequal Pairs of Chromosomes. In accordance with the 

 foregoing classification of structural hybrids it is possible to 

 distinguish provisionally between four kinds of condition which 

 give rise to the occurrence of unequal pairs of chromosomes at 

 meiosis. 



Table 20 

 Classification of Unequal Bivalents 



I. Deficiency, Reduplication or Translocation Heterozygotes. 

 A. Animals, 



Forficula auricularia . . . \ tx^^-J^^'-.t^^'^' o 



•^ ( W. P. Morgan, 1928. 



Brachystola . . . . . \ 



Arphia . . . . .1- Carothers, 1913. 



Dissosteira . . . . . j 



R.A.CyTOIOQY. 6 



