An abbatoir tumour survey showed that lymphosarcoma cases arose at a rate of approximately 2/100,000 cattle slaughtered. No multiple cases occurred in herds. A limited haematological survey showed no evidence of E.B.L. E.B.L. was made a notifiable disease in October 1977. Since then all tumour cases were back-traced and the herd of origin tested by A.G.I.D. test. All herds proved negative. A survey of herds containing imported cattle was started. To date seven herds containing Canadian Holsteins have proved positive serologically. Little spread of infection within the herds has taken place.