During the last few years a number of swine in the Missouri Agricultural Experiment Station† herd have died from hemorrhage, either spontaneous or as a result of minor wounds. All of the affected animals are closely related. It is evident that the blood-clotting mechanism is seriously defective, and a study was initiated in an attempt to classify the abnormality.Bleeding Time. If determined by Duke's method1 the bleeding time is within the normal range. As shown in Table I though, if an incision of any extent is made the bleeding time is prolonged indefinitely.Coagulation Time. The procedure followed is essentially the same as the Lee-White2 modification of Howell's method. The blood sample is taken from an ear vein, collected in cold paraffin coated tubes, and placed in an ice bath. The results reported in Table I show that the coagulation time was 5 times that of normal blood. The blood clots slowly, but after it forms it retracts in normal time.According to the prevailing theory at least 4 components o...