THE TURKEY IMPORTANT IN THE SPREAD OF GAPEWORMS. 11 
worms observed by the writer in chickens 14 days after infection 
has been 17 mm. Usually the length attained in this period is less, 
commonly being 12 to 14 mm. The longest gapeworm observed by 
the writer in chickens measured 21 mm. in length. This was found 
in an old, debilitated chicken, mentioned on page 6, which had been 
infested for an unknown period. Some of the gapeworms present in 
an adult turkey 19 days after infection measured nearly 30 mm. in 
length, and worms measuring 24 mm. were common. In natural cases 
of infestation gapeworms in turkeys have been found commonly to 
measure 30 to 40 mm. in length, and have been found as long as 
50 mm. The measurements given are those of mature females that 
had begun oviposition or that contained eggs ready to be deposited. 
HOW TO AVOID LOSSES IN CHICKENS. 
From what has been determined as to the frequent occurrence of 
gapeworms in turkeys, the susceptibility of old as well as young 
turkeys to gapeworm infection, the diminishing susceptibility of 
chickens to infection as they grow older, and the rarity of gape- 
worms among adult chickens, it would seem that the chief element in 
the spread and maintenance of gapeworm infection, leaving infested 
soil out of consideration, is the turkey. The eggs of the gapeworm 
are scattered over the soil in the feces of infested turkeys. Later 
some of these eggs or the larvae that have hatched from them are 
picked up again by the turkeys and more egg-producing worms de- 
velop in them to add to the number of those already present. Thus 
the stock of young worms in the soil and adult worms in the turkeys 
is maintained. Meanwhile young chickens may also pick up gape- 
worm eggs or larval worms from the ground where the eggs have 
been distributed by the turkeys, with the result that they soon show 
symptoms of gapes. As chickens young enough to be readily sus- 
ceptible to infection with gapeworms usually die from gapes soon 
after they begin to show symptoms of the disease they are not 
likely to add much to the infection already in the soil. Older 
chickens likewise do not scatter much infection because the eggs and 
larval worms that they pick up either do not develop on account of 
the diminished susceptibility of the chickens or, if the worms do 
succeed in developing to egg-producing maturity, they are unlikely 
to survive for more than brief periods. Chickens, therefore, may be 
considered to play a small part, compared with turkeys, in infecting 
the soil with gapeworms, and to be of minor importance as reservoirs 
of infection. By keeping turkeys away from young chickens and 
providing the latter with runs where there have been no turkeys 
within a year or two and where, if used previously by young chickens, 
there have been no cases of gapes in recent years, the danger of losses 
