* From the Department of Genetics (No. 512), University of Wisconsin. This project was supported in part by the Research Committee of the Graduate School from funds supplied by the Wisconsin Alumni Research Foundation. 1 Irwin, M. R., Cole, L. J., and Gordon, C. D., J. Exptl. Zool. 73, 285 (1936). 2 Miller, W. J., Physiol. Zool. (in press). 3 Irwin, M. R., and Cole, L. J., J. Exptl. Zool. 73, 8...