514 ON THE DISTRIBUTION OF MUTANT CHARACTERS 



cells of which belong to the type of laeta. Now, whenever one of the 

 lateral chromosomes mutates and is doubled, this does not seem to 

 affect the sister chromosomes. But each time, when the central 

 chromosome is doubled, all the lateral ones are affected in the same 

 way, at the same time producing one or often a larger number of 

 their possible mutations. "Very manifold groups of forms" (de Vries 

 1913 p. 333) may thereby arise, but their description must be put 

 off till another opportunity. 



LITERATURE CITED 



Blakeslee, A. F., 1922. Variations in Datura, due to changes in chromosome 

 number. Amer. Nat. 56 : 16—32. 



Boedijn, K-, 1920. Die Chromosomen von Oenothera Lamarckiana mut. simplex. 

 Zeitschr. indukt. Abstamm. Vererb. 24: 71 — 76. 



Cleland, R. E., 1922. The reduction divisions in the pollen mother cells of Oeno- 

 thera franciscana. Amer. Journ. Bot. 9 : 391—413. 



Shull, G. H., 1921. Three new mutations in Oenothera Lamarckiana. Jour. Here- 

 dity 12 : 354-363. 



Vries, H. de, 1901. Die Mutationstheorie. Vol. I, xii+648 pp. Leipzig: Veit 

 & Co. 



1913 Gruppenweise Artbildung. vii+365 pp. Berlin: Gebruder Borntraeger. 

 1916 New dimorphic mutants of the Oenotheras. Bot. Gaz. 62 : 249-280. 

 Opera VII, p. 83. 



1918 Kreuzungen von Oenothera Lamarckiana mut. velutina. Zeitschr. in- 

 dukt. Abstamm. u. Vererb. 19: 1-38. Opera VII, p. 317. 



1919 Oenothera rubrinervis, a half mutant. Bot. Gaz. 67 : 1—26. Opera VII, 

 p. 353. 



(Genetics, Bd. 8, 1923, p. 233) 



