300 IMPROVEMENT OF MAN'S ENVIRONMENT 



in your own home block or in the town in which you Hve. Make a 

 map showing the buildings. Locate all houses, stores, factories, 

 etc. Indicate any cases of communicable disease on the map. 

 Mark all heaps of refuse in the street, all uncovered garbage 

 pails, any street stands or push carts which sell uncovered fruit, 

 and any stores which have an excessive number of flies. A sani- 



^Imerican Aluscum oj Natural History, 



Push cart with glass covers to protect fruit from dust and flies. 



tary survey made by the biology class may bring up a number of 

 vital topics not mentioned here and may be of great value in 

 pointing out certain defects or merits of your community. 



Care in Production of Milk. — Milk drawn from a healthy cow 

 should be nearly free from bacteria. But immediately on reaching 

 the air it may receive bacteria from the air, from the hands of th 

 person who milks the cow, from the pail, or from the cow herself. 

 Cows should, therefore, be milked in surroundings that are sani- 

 tary (figure on page 4), the milkers should wear clean garments, 

 put on over their ordinary clothes at milking time, and pails and all 

 utensils used should be kept clean. Especially the surface exposed 

 on the udder from which the milk is drawn should be cleansed before 

 milking. 



