507 



Confining the animals to frequently Hushed artificial 

 tanks will, however, prevent tapeworm infection. 



With chickens, the outlook is somewhat better. An 

 extenninatiou of slugs will insure immunity against 

 Davainea proglottina, but no precise directions can be 

 given to prevent chickens from becoming infested 

 with other tapeworms until the life history of these 

 parasites is better understood. It will be well, how 

 ever, to keep chickens housed in the morning until the 

 sun is well up and the ground is dry, for they will thus 

 be less likely to meet with the supposable intermediate 

 hosts of other worms. 



Absolutely nothing can be done at present looking 

 to a prevention of the transmission of tapeworms of 

 wild birds to the dcinesticated fowls through known or 

 unknown intermediate hosts, except to prevent the 

 domesticated ducks, geese, etc., from visiting ponds. 



There is, however, considerable outlook for improve- 

 ment if different kinds of fowls are alternated in sue 

 ceeding years upon the same ground or if the runs and 

 yards of fowls are occasionally changed. From the 

 table (pp. 554, 555), it will be seen that thus far none of 

 the tapeworms of chickens are known to occur in tur- 

 keys. Whether this immunity of chickens to turkey 

 worms and turkey's to chicken worms is real or appar- 

 ent, however, is yet to be scientifically determined. 

 Should it prove to be real, then an alteration of flocks 

 of turkeys and chickens in diiTerent years will probably 

 insure practical immunity of both birds from any seri- 

 ous outbreaks of tapeworm disease. If. however, tur- 

 keysorchick( ns.as the case may be, are i-aised upon the 

 same grounds year after year, it is cmly natural that 

 those grounds should become thoroughly infested with 

 the lai'val stages of tapeworms and that fresh out- 



