PARASITES AND PARASITIC DISEASES OF SWINE 
3 
yards both these purifying agencies are shut off by trees. In a loca- 
tion open to the trade winds, trees and brush often shield the yard 
from the prevailing breezes which are cool and pleasant. With a 
high humidity in this climate, evaporation and drying of the soil 
is >luggi,sh unless the surrounding air is kept in motion. 
The pest arrangement as far as sanitation is concerned would be 
to eliminate all trees and brush in and around the yard and provide 
a roof shelter for protection from the elements. Otherwise a selec- 
tion and arrangement of shade trees should be made in order that 
the direct rays of the sun can reach all parts of the yard at least 
one-halt' the day. Trees that branch fairly high from the ground 
are good for this purpose. 
PREVENTIVE MEASURES 
If hogs are confined in yards the ground should be kept dry and 
free of growing vegetation. As previously explained, shade is an 
important factor, in connection with moisture or dryness in hog 
Fiot RE 1. — A bare yard for hogs located on a sloping hillside. Farrowing pen and yard 
in background. 
yards. Also shade for the microscopic eggs and larvae of parasites 
on the ground may be provided by any covering that conserves mois- 
ture and prevents the penetration of the direct rays of the sun. 
Therefore all accumulations of left-over feed, especially grass, cane, 
corn husks, etc., should be cleaned up and removed each day with 
the manure. 
On the heavy soils in the wet sections the yards should be placed 
on a slope or hillside to insure proper drainage (fig. 1). Otherwise 
artificial or subsoil drainage must be provided. Any surface water 
accumulations such as mud wallows must be avoided. If the yards 
are properly situated the heavy washing rains during one season and 
the sunlight during both seasons are very effective in carrying away 
