Abstract
The author conducted various investigations on the lung tumors induced in mice by oral administration of 0.25 per cent isonicotinic acid hydrazid (INH) histogenetically. The following, results were thus obtained.
1) Generally speaking, most of tumors were found on the pleural surface.
2) Inflammation and atelectasis showed no particular causative relations with the formation.
3) The majority of the lung tumors (adenoma) induced by administration of INH per os are considered to be alveolar epithelia origin.
4) Malignancy could not be confirmed in the present experiment up to 18th month.
