From Dec. 14 to Dec. 25, 1925, there developed in the city of Cortland, N. Y., eight cases of poliomyelitis. All the patients were found by one of us (A. C. K.) to have consumed milk from the same dealer, Mr. G. December 7, seven days before the onset of the first case of this group, a 16 year old boy (case 1) who was working on the dairy farm where the bulk of G.'s milk was produced, became sick with headache, pain in the back and some diarrhea. He vomited and felt feverish but continued at work, milking from eight to ten of the twenty cows on the dairy, though he noticed that his hands were growing progressively weaker, with pain and tenderness in his left arm. On the morning of December 11, after milking three or four cows, he gave up work on account of paralysis of the