nybom: vegetatively propagated species 289 



54. Heiken, A. 1958. Aberrant types in the potato. Acta Agr. Scand., 



8: 319-358. 



55. . 1960. Spontaneous and X-ray-induced somatic aberra- 

 tions in Solatium tuberosum L. Acta Acad. Reg. Sci. Upsaliensis, 

 7: 1-125. 



56. Heslot, H., Ferrary, R., Levy, R., and Monard, Ch. 1959. Recher- 



ches sur les substances mutagenes (halogeno-2 ethyle) amines, 

 derives oxygenes du sulfure de bis-(chloro-2 ethyle), esters sul- 

 foniques et sulfuriques. Compt. Rend. Seances Acad. Sci., 248: 

 729-732. 



57. Hough, L. F., and Weaver, G. M. 1959. Irradiation as an aid in 



fruit variety improvement: I. Mutations in the peach. Jour. 

 Hered., 50: 59-62. 



58. Howard, H. W. 1958. Transformation of a monochlamydius into 



a dichlamydius chimaera by X-ray treatment. Nature, 182: 1620. 



59. Jank, H. 1957. Experimentelle Mutationsauslosung durch Rontgen- 



strahlen bei Chrysanthemum indicum. Ziichter, 27: 223-231. 



60. Johnson, G., and Schaal, L. A. 1957. Chlorogenic acid and other 



orthodihydrophenols in scab-resistant Russet Burbank potatoes. 

 Phytopath., 47: 253-255. 



61. Julen, G. 1954. Observations on X-rayed Poa pratensis. Acta Agr. 



Scand., 4: 585-593. 



62. . 1958. Ueber die Effekte der Rontgenbestrahlung bei 



Poa pratensis. Ziichter, 28: 37— 40. 



63. Kaplan, R. W. 1953. Ueber die Moglichkeiten der Mutationsaus- 



losung in der pflanzenzuchtung. Zschr. f. Pfl. Ziichtung, 32: 121- 

 131. 



64. Klein, L. G. 1957. What is new in apple color sports? New York 



State Agr. Exp. Sta. Farm Research, 23: No. 4, 14. 



65. Knight, R. L., and Keep, E. 1957. An early sport of a red currant. 



Ann. Rpt. East Mailing, 1957: 74. 



66. Lewis, D. 1949. Structure of the incompatibility gene: II: Induced 



mutation rate. Heredity, 3: 339-355. 



67. and Crowe, L. K. 1954. The induction of self-fertility in 



tree fruits. Jour. Hort. Sci., 29: 220-225. 



68. MacKey, J. 1951. Neutron and X-ray experiments in barley. Here- 



ditas, 37: 421^84. 



69. Mashimo, I., and Sato, H. 1959. (X-ray-induced mutations in sweet 



potato.) Jap. Jour. Breeding (Japanese), 8: 233-237. 



70. Matsumura, S., and Fujii, T. 1957. Induction of bud-sports by 



X-rays and gamma-rays. Ann Rpt. Nat. Inst. Genetics (Japan), 

 8: 94-95. 



