LIFE HISTORY OF ASCAEIS LUMBRICOIDES. 35 



October 19, 1917: Hixtli j,^ine,i pig died from iniouiiioiiia 8 days after feed- 

 ing. Larva very numerous in lungs, several in trsichea and esophagus. Not 

 found in liver, spleen, stomach, small intestine, uterus, or Fallopian tubes. 



Experiment No. 10. 



June 15, 1918: Fed 6 guinea pigs with eggs of Ascarig suum incubated 

 since April 2. 



June 19, 1918: Killed first guinea pig 4 days after feeding. Lungs in- 

 tensely hemorrhagic. Numerous larvae in lungs, also unhatched eggs. Larvae 

 in lungs measured 0.31 to 0.4.5 nmi. in length. Liver, trachea, esophagus, 

 negative. Other organs not examined. All the guinea pigs showed symptoms 

 of pneumonia evidenced by dyspnea and abdominal breathing. 



June 20, 1918 : Guinea pig No. 2 died 5 days after feeding. Lungs intensely 

 hemorrhagic, unhatched eggs in lungs. Larvae in lungs, trachea, and pharynx. 

 None in liver or small intestine. Other organs not examined. Measurements 

 of larvre in different organs as follows : Lungs, 0.35 to 0.83 mm. in length ; 

 trachea, 0.5 to 0.88 mm. ; pharynx, 0.5 to 0.98 mm. 



June 21, 1918 : The 4 remaining guinea pigs died 6 days after feeding. Post- 

 mortem on third guinea pig showed pneumonia with red hepatization of the 

 lungs; numerous larvae in lungs, one in pharynx, none in trachea, liver, or 

 spleen. Other organs not examined. Measurements of larvae in different organs 

 as follows : Lungs, 0.63 to 0.93 mm. ; pharynx, 0.9 mm. 



June 26, 1918: Fourth guinea pig examined (kept in refrigerator since 

 death, June 21). Lungs hemox-rhagie, containing numerous larvae. Several 

 larvae in trachea ; other organs not examined. 



June 27, 1918: Fifth guinea pig examined (kept in refrigerator since death, 

 June 21). Numerous larvae in lungs, which were in a stage of red hepatization. 

 Spleen and liver negative. Other organs not examined. 



June 29, 1918: Sixth guinea pig examined (kept in refrigerator 8 days since 

 death). Lungs heavily infested; several larvae in trachea; larvae in lungs and 

 trachea, actively motile 8 days after death of host. Measurements of larvae 

 in different organs as follows : Trachea, 0.6 to 0.9 mm. ; lungs, 0..53 to 0.9 mm. 



The presence of unhatched eggs in the lungs of 2 of the guinea pigs may be 

 explained by assuming that some of the eggs passed down the trachea instead 

 of the esophagus, when the animals were being forcibly fed with a pipette. 

 This explanation is strengthened by the fact that we have never seen unhatched 

 eggs in the lungs of mice which were infested by being allowed to eat contami- 

 nated food without compulsion. 



That Ascaris larvae can live for some time after the death of the host is shown 

 in this experiment in which larvae in the lungs and trachea were seen to be 

 actively motile 8 days after the host animal died. Apparently, however, no 

 growth occurred during this period, since larvae from the lungs of the guinea 

 pig which was examined on the day of its death measured 0.63 to 0.93 mm. 

 (maximum and minimum of 10 specimens), while larvae from the lungs of the 

 guinea pig which had been dead 8 days measured practically the same — 0.53 

 to 0.9 mm. (9 specimens). 



Experiment No. 11. 



October 29, 1917 : Fed 2 guinea pigs at 11 a. m. with about 3.6 cubic centi- 

 meters of a culture of eggs of Ascaris suum in weak formalin. Culture started 

 September 1. 



October 30, 1917 : Killed 1 guinea pig at 3 p. m., 28 hours after feeding, 

 bled from neck, catching blood in test tube. Centrifuged with an equal amount 

 of 1 per cent sodium-citrate solution. No larvae found. 



