HINDRANCES AND DISEASES. 101 



that they are the prime means of spreading the gapes. 

 More recent experiments show that while earthworms in 

 infected soils often contain the embryos, the earthworm 

 is not a necessary host, because the disease is found where 

 earthworms are not natural to the soil. Dr. Walker still 

 maintains that if chicks are kept from eating earthworms, 

 they will not have the gapes. He argues that without 

 the aid of earthworms to carry gapeworms below the first 

 line, they would soon be exterminated in the North. He 

 admits that chicks fed on fresh eggs of the gapeworm 

 might not contract the disease, but thinks it is perhaps 

 because their digestion is so rapid that the eggs pass off 

 before they have time to hatch. Older chicks are not so 

 susceptible, because they have more power to dislodge the 

 worms from the trachea, and are not embarrassed by a few. 



Wherever gape-infected chicks or poults have long been 

 kept, the ground becomes infected with the germs, and re- 

 mains infected just as long as chickens are kept there. 

 Curing the birds will not remove the infection, but if no 

 poultry are kept for a sufficient length of time, the infec- 

 tion dies out for want of necessary conditions for develop- 

 ment. It is folly to put young chicks on a plat of ground 

 or field infected with gapeworms, unless the soil is freed 

 from contamination. This can be done by spreading half 

 a bushel of fresh air-slaked lime on every hundred square 

 feet of ground. Chicks kept in pens for eight weeks, the 

 soil of which has thus been purified, usually escape infec- 

 tion. The same quantity of coarse salt may be used in 

 place of the lime, but it must be dissolved by water or 

 rain before the chicks are put in, or they may eat it and 

 die. Avoid giving water from an infected source. For 

 destroying the infection in the soil, water containing a 

 large quantity of salicylic acid or sulphuric acid is recom- 

 mended by Megnin. 



There are many very old and effective remedies for re- 

 moving gapeworms. Air-slaked lime has long been usecl 



