ROBERT J. ECKROADE,^* GABRIELE M. ZU RHEIN,^** WILLIAM FOREYT<sup>***


*</sup>Department of Veterinary Science, University of Wisconsin, Madison, Wisconsin.
^**Department of Pathology, Medical School, University of Wisconsin, Madison.
^***Formerly, Department of Veterinary Science, University of Wisconsin, Madison, Presently, United States Army, South Vietnam.