1. Three cases of situs inversus are described and the clinical and aetiological factors are discussed briefly.
2. This abnormality occurring in father and son whose family history indicates a great degree of consaguinity seems to support the view held by Cockayne that it is a recessive inheritance.
3. Situs inversus when complete seems to cause no disability. When incomplete as in examples of isolated dextrocardia, congenital heart diseases are commonly seen in association with it. Other congenital malformations may also co-exist. Recently the syndrome of hypertrophic rhinitis, nasal polyposis and sinusitis and bronchiectasis have been encountered in association with transposition of the viscera.