GENETIC VARIATIONS 339 



H. J. Muller and E. Altenburg (1930), The Frequency of Transloca- 

 tions Produced by X-rays in Drosophila. Genetics, vol. 15, pp. 283— 

 311; H. J. Muller (1932), Further Studies on the Nature and 

 Causes of Gene Mutations. Proceedings of the Sixth International 

 Congress of Genetics, vol. i, pp. 213-255. 



The papers above listed contain references to a large part of the 

 extensive literature on this subject. 



5. Page 330. The account given above is based mainly on the paper 

 of Muller, 1932, listed above. 



6. Page 333. J. Schultz and T. Dobzhansky (1934), The Relation 

 of a Dominant Eye Color in Drosophila melanogaster to the Associated 

 Chromosome Rearrangement, Genetics, vol. 19, pp. 344—364. 



7. Page 336. On the position effect, see the paper cited in Note 6: 

 also the papers therein referred to. 



8. Page 336. On such diverse types in Datura, see A. F. Blakeslee 

 (1929), Cryptic Types in Datura. Journal of Heredity, vol. 20, pp. 

 177-190. For the conditions in Oenothera, see R. E. Cleland and 

 A. F. Blakeslee (1931), Segmental Interchange, the Basis of Chromo- 

 somal Attachments in Oenothera. Cytologia, vol. 2, pp. 175—233. 



