1. Fink, B. R., and Kenny, G. E., Fed. Proc., 25, 56 (1966).
2. Rector, G. H. M., and Eastwood, D. W., Anesthesiology, 25, 109 (1964).
3. Blandau, R. J., Boling, J. L., and Young, W. C., Anat. Rec., 79, 453 (1941).
4. Walker, D. G., and Wirtschafter, Z. T., The Genesis of the Rat Skeleton, 6 (Charles C. Thomas, Springfield, Illinois, 1957).
5. Tricomi, V., Serr, D., and Solish, G., Amer. J. Obstet. Gynec., 79, 504 (1960).