The frequency of obsolete tubercle m persons who have died from gastric cancer has often been the subject of remark. In our own series one or both lungs presented signs of former tuberculosis in 15.8 per cent., while Lebert observed a similar condition in 14.7 per cent, of his cases. Although estimates relative to the frequency of the pulmonary lesion among persons who have died from all causes vary from 4.7 per cent. (Heitler) to 44 per cent. (Schlenker), it is probable that of all diseases carcinoma is most often associated with obsolete tubercle. On the other hand, most authorities are agreed that the two complaints rarely coexist in an active state in the same individual, and that when carcinoma commences the tubercle usually ceases to progress. In one case of this kind, which we were able to watch throughout its course, a rapid tuberculosis of the lungs and intestines came suddenly to a halt when symptoms of malignant disease of the stomach and pancreas made their appearance, and after death, at the end of eight months, not only was the pulmonary lesion found to be completely quiescent, but more than thirty ulcers in the bowel had either partially or entirely cicatrised. It is probable, therefore, that while the two diseases are not wholly incompatible, the tubercle bacillus is unable to flourish in the same body as carcinoma. On the other hand, there is evidence to show that a proclivity to tuberculosis distinctly favours the inception of cancer. Among the general community a family history of tubercle exists from 10.8 (Dovey) to 28.5 per cent. (Kuthy), while Roger Williams found a similar history in 50 per cent, of his cases of uterine and mammary cancer, and 26 per cent, of our gastric cases possessed one or more near relatives who had succumbed to phthisis. It is also interesting to observe that the progenitors of cancerous families are often themselves the sole survivors of tuberculous families, and that while the cancerous proclivity shows itself most often in the elder children (Moore), the younger ones not infrequently succumb to consumption. In other instances cancer and phthisis alternate in successive generations.