46 VARIATIONS IN THE LOWER FUNGI 



Fig. 28. H\'brid fungi. Giant colonies from eight different sporidia of Ustilago 

 Zeae obtained from smut spores resulting from a crossing of two strains of 

 corn smut parasites. From J. J. Christensen, Minn. Agr. Exp. Sta. (St. Paul), 



Tech. Bull. 65 (1929). 



LITERATURE 



1. Alexander, A., Ueber die faviforme Degeneration resp. Unwandlung unserer 



Dermatophyten, Dermatol. Z., 56, 225 (1929). 



2. Barnes, B., Variations in Eurotium herbariorum (Wigg.) Link, induced by 



the action of high temperatures, Ann. Botany, 42, 783 (1928); Variations 

 in Botrytis cinerea induced by the action of high temperatures, Ann. 

 Botany, 44, 825 (1930); Induced variation. Trans. Brit. Mycol. Soc, 20, 

 17 (1935). 



3. BiLTRis, R., Sur la variabilite des caracteres de I'espece chez les derma- 



tophytes, Ann. inst. Pasteur, 43, 281 (1929). 



4. Brierley, W. B., Variation in fungi and bacteria, Proc. Intern. Congr. Plant 



Sci., Ithaca, 2, 1629 (1929). 



5. BuRKHOLDER, W. H., Variations in a member of the genus Fusarium grown 



in culture for a period of five years. Am. J. Botany, 12, 245 (1925). 



6. Chodat, F., Recherches experimentales sur la mutation chez les champi- 



gnons. Bull. soc. hot. Geneve, Ser. 2, 18, 41 (1926). 



7. Christensen, J. J., Mutation and hybridization in Ustilago zeae, Minn. 



Agr. Exp. Sta. Tech. Bull. 65 (1929) ; Studies on the genetics of Ustilago 

 zeae, Phytopath. Z., 4, 129 (1931). 



8. Davidson, A. M., E. S. Dowding, and A. H. R. Buller, Hyphal fusions in 



dermatophytes. Can. J. Research, 6, 1 (1932). 



9. Demerec, M., Unstable genes, Botan. Rev. 1, 233 (1935). 



10. Dickson, H., The effects of x-rays, ultraviolet light and heat in producing 

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 Aim. Botany, 47, 735 (1933). 



