THE TUKKEY IMPORTANT IN THE SPREAD OF GAPEWORMS. 5 



ture, those in the trachea evenly distributed from bronchi to larynx. 

 The females in the trachea measured 3 to 6 mm. in length. The 

 worms in the trachea were enveloped in masses of very viscid, tena- 

 cious mucus and none apparently were attached to the wall of the 

 trachea. Another chicken was killed 11 days after feeding and was 

 found to be free from parasites. Twenty-eight days after feeding, 

 microscopic examination failed to show gapeworm eggs in the feces 

 of the three surviving chickens. The following day one of them was 

 killed and found to be free from parasites. Thirty-one days after 

 the first feeding the two surviving chickens were fed with a gape- 

 worm culture. Eight days after this feeding the chickens were 

 killed. One of them was free from parasites, the other had one 

 young worm in the lungs, and a pair of coupled worms in the 

 trachea. The female of this pair was ruptured in removal but 

 measured 15 mm. or more in length and contained eggs ready for 

 oviposition. This pair of worms was enveloped in a mass of tena- 

 cious mucus. Evidently the worms in the trachea came from the first 

 feeding of gapeworm material, 39 days before the chicken was 

 killed. 



The findings in the case of one of the chickens referred to sug- 

 gest very strongly that the worms that had succeeded in establishing 

 themselves in the trachea were having difficulty in maintaining them- 

 selves, as 10 of the 15 males present 29 days after infection were 

 dead though firmly attached to the trachea, and as the living worms, 

 both males and females, were enveloped in a thick layer of mucus, 

 indicative perhaps of a strong reaction, on the part of the host, that 

 would soon destroy them. In two of the other chickens also the 

 unusually large masses of mucus enveloping the worms suggest the 

 likelihood of the early death or expulsion of the parasites. In any 

 event it is evident, since in the one instance a large proportion 

 of the gapeworms present 29 days after infection had died after 

 reaching maturity, that gapeworms in adult chickens, when they 

 succeed in establishing themselves in the trachea, sometimes die 

 within a month after infection, infestation with gapeworms in 

 such cases thus being of brief duration. Further evidence of the 

 transient nature of gapeworm infestation in adult chickens is 

 given by Waite (1920, p. 115), who fed about 150 earthworms 

 from gapeworm-infested chicken runs to three yearling hens. Fif- 

 teen days later gapeworms could be distinctly seen in the tracheas 

 of two of them by looking down their throats in a good light. Two 

 weeks later the worms had disappeared, and when the hens were 

 killed and examined 72 days after the feeding with the earthworms, 

 no signs of gapeworms were found. 



In view of the difficulty of infecting adult chickens with gape- 

 worms, the likelihood of the brief duration of infestation in cases in 



