At this stage in our knowledge, it is generally agreed that the blood group -characters on the erythrocytes of man and animals and the different serum proteins and groups should all be classified as gene markers, or blood groups. This view is held by Race and Sanger (1959) who-introduced a paper on the subject of 'the inheritance of blood groups with this statement "'Blood groups', in a broader sense could nowadays include not only the differences due to the antigens of red calls, white cells and platelets, but also the distinctions made by the various haemoglobias, haptoglobins and Gm serum groups."Tho knowledge and value of blood groups in man has been manifest in clinical transfusion, and in solutions to medicolegal Problems of disputed parentage, and forensic medicine. They have also been applied in anthropological studies. In domestic animals, however, the knowledge of blood groups has not found comparable bereft in application to clinical transfusion, but has in solving problems of parentage. It has also found application in the detection of heterosis in highly inbred lie b of chickens (Braes, 1953 ,1-1(1 Gilmour, 1954), and in helping to distinguish two egg from one egg twins in cattle. With the advent of progeny testing of piga on a national scale in this country, the necessity for a systematic study of heritable characters such as 'blood groups' seemed essential in this species. In this respect it could be applied as an independent check on pedigree registrations, and to other fields of interest, such as heterozygous advantage and linkage with production characters. The dissertation presented for examination describes the application of immunologioal, serological and biophysical techniques to the discovery and characterisation of 'blood groups' in the pig. The independence and interrelationship of these groups has also been investigated and is discussed
