1. Schwimmer, M., and Schwimmer, D., in Algae, Man and the Environment (edit. by Jackson, D. F.), 279 (Syracuse Univ. Press, Syracuse, 1968).
2. McElhenney, T. R., Bold, H. C., Brown, jun., R. M., and McGovern, J. P., Ann. Allergy, 20, 739 (1962).
3. Brown, jun., R. M., Larson, D. A., and Bold, H. C., Science, 143, 583 (1964).
4. Bernstein, I. L., and Safferman, R. S., J. Allergy, 38, 166 (1966).
5. Overeem, M. A. van, Rec. Trav. Botan. Neerl., 34, 388 (1937).