PLAN OF THE PLANT 51 
Community system is a term applied to that method of housing 
in which the birds are confined in large flocks under one roof. 
The poultry houses are usually of the long-house type; in some 
cases as long as five hundred feet. The yards, if any, run to the 
front, and in some cases both to the front and to the rear. In 
this system the amount of land required is relatively small, 
considering the large number of birds kept. It is well adapted 
to egg farms located on expensive land very near large centres 
of population. The birds are closely confined and under observa- 
tion at all times. The disadvantages are danger of fire and dis- 
Fia. 36.—Houses and yards on a hillside, giving good drainage. 
ease, and extra expense required for fencing. This type of long 
house is often used with only one or two yards. The house is 
then not divided into small pens, as many as five hundred birds 
being kept in one flock (Fig. 32). 
Semi-community is a term applied to plants in which the birds 
are kept in smaller units, consisting usually of single or, at the 
most, double pen-houses arranged along streets or roads, with 
yards running to the front or rear. The pens are from twenty- 
five to one hundred feet apart, depending on the length of the 
tuns. This type requires more land than the former, and more 
labor to attend. Advantages are: Giving birds much more room 
and reducing the risk of the transmission of disease. 
These first two systems are suited to the production of market 
