36 BULLETIN 817;, TJ. S. DEPT. OF AGRICULTUKE. 



October 31, 1917: Two days after feeding, second guinea pig etlierized about 

 2 p. m. and when entirely anesthetized tlie abdomen was opened and blood drawn 

 by a syxunge directly from the portal vein, the blood being delivered into a 

 test tube containing 5 cubic centimeters of a 5 per cent solution of acetic acid 

 and centrifuged. The second specimen of the sediment taken for examination 

 fi-om the bottom of the tube contained two larvse about 0.28 mm. long. 



It appears from the experiment above that 48 hours after feeding cultures of 

 Ascaris eggs, Ascaris larvae may be found in the blood in sufficient numbers to 

 be demonstrated in the portal circulation, but' the results of a single experiment 

 such as this can not be accepted as conclusive. 



Experiment No. 12. 



November 3, 1917 : Fed 3 guinea pigs with culture of Ascaris suum. 



November 5, 1917 : Two days after feeding killed and examined blood of first 

 guinea pig, keeping portal system and systemic system separate, using 3 per 

 cent acetic acid, same technique as in previous experiment. Both liver and 

 blood negative. 



November 6, 1917 : Three days after feeding killed and examined second 

 guinea pig, drawing blood from pulmonary artery. One larva seen. Two 

 larvfe in lungs ; none in liver. 



November 9, 1917 : Third guinea pig died from pneumonia six days after feed- 

 ing. Many larvte in lungs, several in trachea, one in esophagus, one in small in- 

 testine, none in liver. 



It appears from the above experiment that the larvte after leaving the liver 

 are carried by the systemic circulation to the heart and thence by the 

 pulmonary artery to the lungs. In this experiment as early as three days after 

 infection a few larvae had already entered the lungs and as none were found 

 in the liver it is possible that most of the larvte were in the blood stream on 

 the way to the lungs. The results of a single experiment such as this, how- 

 ever, can not be accepted as conclusive. 



Experiment No. 13. 



November 22, 1917: Three guinea pigs in.iected subeutaneously with Ascaris 



suum eggs. 



November 30, 1917 : Killed first guinea pig eight days after injection. Larva 

 in lungs, 0.5 mm. long. Abscess at site of injection contains Ascaris eggs, the 

 embryos dead and unhatched. Spleen, trachea, and esophagus negative ; lungs 

 with hemorrhagic spots. 



December 4, 1917: Killed second guinea pig 11 days after injection. Larva 

 in lungs, 1.5 mm. long ; one anterior lobe of lung chocolate brown ; a few 

 hemorrhagic spots over the rest of the lungs. Spleen, trachea, and esophagus 

 negative. Unhatched eggs containing vermiform embryos in abscess at site 

 of injection. 



December 4, 1917: Killed third guinea pig 11 days after injection. Lungs 

 showing extensive inflammation and covered with dark hemorrhagic spots. 

 Larvae in lungs; one measured 1.3 mm. in length. Larvae in trachea measuring 

 1.5 mm. Spleen and esophagus negative. Eggs in abscess under skin at site 

 of injection. Some empty shells. Embryos in eggs dead. 



The experiment of injecting Ascaris eggs beneath the skin was repeated, 

 six g-uinea pigs being used. Similar results were obtained, the larvae being 

 found in each case in which the lungs were examined a week to 10 days after 

 injection of the eggs. 



