Cases of Hydatid Cyst in the lungs are not common in this country, and it is unusual to meet them in the upper lobe of a child eleven years old. B— K—, aged 11, was brought to the O. P. department of the Lincoln County Hospital on November 13, 1929. He was complaining of pain in his lower abdomen of two months' duration, the pain was of a dull aching character uninfluenced by food, his appetite had been fairly good but he was losing weight. He had some cough, more troublesome at night, and his sputum was said to be thick. He was sent to my department November 21, 1929. The diaphragm movement on the right side was restricted, there was a well-marked opacity in the upper lobe of the right lung, very well defined; this will be seen in the picture. There was no alteration in the opacity with change of position. The boy was admitted to hospital, December 3, 1929; his abdominal pain had gone and his cough was less. Physical signs: Slight flattening of right apex in front ? Slight diminution movement behind. Per...