During the past several years thirteen cows have died in the dairy herd at the Virginia Polytechnic Institute of malignant tumors of the lymphoid type. In view of research with respect to cancers of various types in man, any information relating to tumors acquired in this study should be of value not only to animal industry but also to similar conditions in in man A problem such as this requires long study, probably several years. This paper is a preliminary report on early fundamental steps of the cancer problem in dairy cattle as applied to local conditions. Because spontaneous cases of neoplasms in dairy cattle do not occur with any regularity, other phases of cancer research were instituted for investigation during the interval between cases. From the results of the previously described experiments, the following conclusions were drawn: 1. There was no evidence whatever of the neoplasms occurring in the rats about the dairy bards. 2. The attempts to produce neoplasms in dairy cattle due to foreign bodies implanted in the rumen were unsuccessful. 3. Attempts to transplant some of the tumors occurring naturally in the dairy cattle were unsuccessful. 4. Attempts to produce neoplasms in dairy cattle by weekly injections of four per cent solution or tar and lard were unsuccessful. 5. Attempts to produce tumors in fowl by weekly injections of four per cent solution or tar and lard were successful in five of the nine birds. Attempts to transplant two of these tumors were unsuccessful. 6. Occurrence of tumors in the members or the two families indicates possible genetic relationship. / Master of Science