1. Lodder, J., and Kreger-van Rij, N. J. W., The Yeasts; A Taxonomic Study (North-Holland Publishing Co., 1952).
2. Hansen, E. C., Medd. Carlsb. Lab., 1, 159 (1886).
3. Levine, S., and Ordal, J. J., J. Bact., 52, 687 (1946).
4. Nickerson, W. J., and Edwards, G. A., J. Gen. Physiol., 33, 41 (1949).
5. Nickerson, W. J., and Chung, C. W., Amer. J. Bot., 41, 114 (1954).