The technique of the conglutinating complement absorption test, which has been used to detect antibody in pigs infected with Ascaris, and the method employed for rendering pig serum suitable for use in this test, have been described.

Antibodies against Ascaris can be detected by the use of the following antigens: (1) An alcoholic extract of ovaries, oviducts and uteri of the female adult Ascaris. (2) Boiled and unboiled saline extracts of whole worm. (3) Polysaccharide fraction of whole worm.

On an examination of antisera from pigs infected with Oesophagostomum dentatiim, no cross-reaction between Oesophagostomum and A. sttum was observed using a saline extract of whole Ascaris worm as antigen.

1. Capillaria obsignata Madsen, 1945 is described from the small intestine of the Black Swan (Cygnus atratus) for the first time.

2. The description of C. obsignata from the Black Swan is compared with the descriptions of C. anseris Madsen, 1945, C. droummondi Travassos, 1915 and C. obsignata from the domestic fowl, and it is concluded that C. anseris and C. droummondi are synonyms of C. obsignata.

3. Capillaria anatis and Trichostrongylus tennis are recorded from the Black Swan as new host records.