82 BULLETIN 140, UNITED STATES NATIONAL MUSEUM 



farther back in relation with the bursal expansion preceding the 

 portion which narrows to the point of the tail. Schneider refers to 

 9 pairs and figures 9 in his diagram and 12 pairs with 1 extra and 

 variable papilla in his plate figure. The spicules are subequal, alate, 

 and about 4 mm. long, according to some writers, or the short one 

 2 mm. long and the other 2.5 mm. long, according to Smit ; they ter- 

 minate in small buttonlike enlargements. 



Female 60 to 120 mm. long. Tail 1/50 to 1/60 of body length, 

 its end straight, conical, and mucronated. Vulva in the anterior por- 

 tion of the body, dividing body length in ratio of 38:49. Eggs 

 ellipsoidal, 75 to 80/* long by 45 to 50/* wide, not segmenting, as a 

 rule, when oviposited. 



Life history. — A female worm may contain over 1,200 fertilized 

 eggs, or, according to Danheim, approximately 1,500. With suffi- 

 cient moisture, these eggs will develop to a point where each egg 

 contains an infective embryo in 9 or 10 days, when incubated at a 

 temperature of 28° C. ; at less favorable temperatures this develop- 

 ment may require weeks. Hatching normally occurs after these in- 

 fective eggs are swallowed by suitable fowls, though an occasional 

 egg hatches without being swallowed. Within 28 hours after swal- 

 lowing infective eggs, according to Ackert, the fowl shows young 

 worms free in the small intestine. Ackert has reported finding the 

 larvae penetrating the intestinal mucosa to some extent. According 

 to the Oklahoma Experiment Station, the larvae migrate to the lungs 

 and here they reach a length of 2 to 3 mm. They then ascend the 

 windpipe and are swallowed, completing their development in the 

 intestine. In 30 days they are half-grown. The possibility that 

 all or part of the young worms may have a migratory phase similar 

 to that of Ascaris lumbricoid,es was suggested by the fact that Ackert 

 found 7 larvae in the lungs, 1 in the trachea, and 2 in the liver in 

 feeding experiments. Ransom and also Schwartz do not find evi- 

 dence of larval migration. Ova will survive 7 days exposure to sun- 

 light at 23° to 33° C. or 15 hours freezing at -11.6° to — 8°C. Scott 

 has pointed out that the earthworm (Helodrilus parvus) may be a 

 means of spreading the eggs. 



Distribution. — Cosmopolitan (North and South America, Europe, 

 Africa, Asia, and Australia). 



Schwartz (1925) has pointed out, after a study of specimens from 

 various parts of the United States, that it is not Ascaridia galli which 

 is found commonly in chickens in this country, but A. lineata. 

 Therefore, the life history experiments cited above and other reports 

 of this species in the United States, probably should be referred to 

 A. lineata. 



