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LIFE HISTORY OF ASCARIS LUMBRICOIDES. 39 
October 19, 1917: Sixth guinea pig died from pneumonia 8 days after feed- 
ing. Larvze very numerous in lungs, several in trachea 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 Ascaris suum incubated 
since April 2. 
June 19, 1918: Killed first guinea pig 4 days after feeding. Lungs in- 
tensely hemorrhagic. Numerous larve in lungs, also unhatched eggs. Larve 
in lungs measured 0.31 to 0.45 mm. in length. Liver, trachea, esophagus, 
negative. Other organs not examined. All the guinea pigs showed symptoms 
of pneumonia evidenced by dyspnea and abdominai breathing. 
June 20, 1918: Guinea pig No. 2 died 5 days after feeding. Lungs intensely 
hemorrhagic, unhatched eggs in lungs. Larve in lungs, trachea, and pharynx. 
None in liver or small intestine. Other organs not examined. Measurements 
of larve in different organs as follows: Lungs, 0.385 to 0.88 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 larve in lungs, one in pharynx, none in trachea, liver, or 
spleen. Other organs not examined. Measurements of larve 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 hemorrhagic, containing numerous larve. Several 
larvee in trachea ; other organs not examined. 
June 27, 1918: Fifth guinea pig examined (kept in refrigerator since death, 
June 21). Numerous larve 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 larve in trachea; larve 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 larve can live for some time after the death of the host is shown 
in this experiment in which larveze 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 larve from the lungs of the guinea 
pig which was examined on the day of its death measured 0.638 to 0.938 mm. 
(maximum and minimum of 10 specimens), while larve 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 suwm 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 larve found. 
