LIFE HISTORY OF ASCARIS LUMBRICOIDES. 41 



in regard to the first pig which tiled of veriuiuous piu'uiiiouia. The lieavy 

 infestation in this case could not conceivably have resulted in any other way 

 than Ironi tlie massive dose of eggs given 7 days belore. In regard to the 

 second pig wliich was found infested with intestinal ascari<is 44 days after 

 the initial feeding of eggs, it is less certain that the worms came from the eggs 

 that were fed. Yet the fact that all the worms found were of nearly the same 

 size and, assuming that it takes about 2i mouths for adults to develop in the pig, 

 as it has been shown Is necessary in the case of the human Ascaritf, the facts that 

 the worms were innuature and of a size that might reasonably be expected after 

 44 days of growth, are not inc<msistent witli the presumption that the worms 

 found came from the eggs that were fed to the animal. 



Experiment No. 20. 



Two young suckling pigs were use<l, one fed with eggs of Ascaris lumbri- 

 coides contaiuing vermiform embryos, the other reserved as a check animal. 

 Both pigs and the sow were transferred to a clean board pen soon after the 

 pigs were born and the feces of the sow were frequently examined for evidences 

 of Ascaris infestation. Throughout the experiment ' the feces were negative. 

 Eighty-one days after the feeding with Ascaris eggs the pig was slaughtered but 

 no Ascaris was found in the small intestine nor in any of the organs usually 

 invaded by the larvfe. Seventeen days later the check animal was slaughtered 

 and was also found free from Ascaris infestation. Some of the same culture of 

 eggs used in this experiment was fed to guinea pigs, w^hose lungs became 

 heavily infested with larvse, so there is no question as to the viability of the 

 eggs. 



Experiment No. 21. 



In this experiment 5 neA\'boru pigs were used, date of birth, March 22, 1917. 

 Three pigs were fed with the same culture of eggs used in Experiment No. 20, 

 and 2 pigs were kept as checks. All 5 were kept with the sow in a recently 

 built clean pen. 



March 30, 1917 : First pig received about 5 c. c. of a culture of eggs of Ascaris 

 lumbricoides. Second pig received about 6 c. c. Third pig received about 4 c. c. 



April 8, 1917; Pig No. 2 died 9 days after feeding. The lungs were spotted 

 with numerous ecchymoses but not intensely hemorrhagic as in laboratory ani- 

 mals dying of verminous pneumonia. The spleen and thyroid were negative. 

 One larva was found in the liver, the lungs were heavily infested, larvse were 

 numerous in the trachea, while one larva was found in the pharynx and one 

 in the esophagus. Larvie in the trachea varied from 0.85 to 1.04 mm. in length, 

 with esophagus from 0.09 to 0.13 mm. long. 



May 6, 1917 : Sow removed from the pen. While with the pigs four fecal 

 examinations were made at intervals, all of which proved negative. 



June 8, 1917 : First pig slaughtered and examined 65 days after feeding. 

 Lungs showed lesions of broncho-pneumonia. There were 2 large hemorrhagic 

 areas in which 2 degenerated Ascaris larvae were seen. Trachea, esophagus, 

 stomach, intestines, spleen, and liver were negative for Ascaris. 



July 5, 1917: The third pig was slaughtered 97 days after feeding. Lungs, 

 bronchi, trachea, esophagus, small and large Intestines were all examined, but 

 no Ascaris found. 



July 17, 1917: Fourth pig (check animal) slaughtered and examined 109 days 

 after feeding pigs 1, 2, and 3. Negative for Ascaris. 



July 26, 1917: Fifth pig (second check animal) slaughtered and examined 118 

 days after feeding pigs 1, 2, and 3. Negative for Ascaris. 



