EXPLANATION OF DIAGRAM II. 
A, B, and K are dairy farms selling their product to retail milk 
dealer H. K is the farm on which a case of scarlet fever occurred 
antedating the outbreak in Norwalk. 
The large square TOWN represents the city of Norwalk. 
H is the retail milk dealer among whose customers all cases but two 
occurred. The dash lines represent H’s milk route, and each dot is a 
case of scarlet fever. 
C, D, E, F, G, I, and J are other dairymen having routes in Nor- 
walk. The lines extending from them into the city represent their 
milk routes and are introduced to show their freedom from the 
disease. 
