F. H. Stewart 39 
the mouth, and found larvae not only in the liver and lungs, but in the 
abdominal cavity, spleen, pancreas, kidney, and pleural sacs. 
He found larvae in the tissues at very short periods after infection, in one 
experiment in the pleura, lungs, abdominal cavity, liver, spleen, pancreas, and 
kidney after 20 hours only. 
(4) I (Stewart, 1920) published a short summary of past work, and of some 
of the facts of distribution, and of the clinical importance of the parasite. 
II. The author’s experiments during 1920. 
The experiments dealt with in the present paper were conducted in the 
Lister Institute of Preventive Medicine during the summer of 1920, the cost 
of the animals used being borne by a grant from the Medical Research 
Council. The specimens secured were examined partly at the Lister Institute 
and partly at the Quick Laboratory, Cambridge. My thanks are due to the 
governing body of the Lister Institute, to the Medical Research Council, 
to Dr C. J. Martin and Dr MacConkey for much assistance, to Prof. Nuttall 
for his kind permission to work in the Quick Laboratory and for his help, and 
to Messrs C. and T. Harris of Caine for the supply of material. 
The objects of the experiments were: (A) To ascertain whether after the 
administration of ripe eggs of A. suilla to pigs, the resulting worms could live 
and develop in the intestine after the 14th day. The experiments described 
in Part IV (Stewart, 1919), had traced the life-historv to the 14th day, but 
I had failed to recover worms on the 19th day. (B) To observe whether 
larvae of A. suilla, passed in the faeces of mice, could infect pigs. 
(A) Experiments in which eggs of A., suilla were administered to four pigs. 
11. vi. 20. Ripe eggs of A. suilla from cultures 30-45 days’ old, were given to four 
sucking pigs aged three days. Each pig received 20,000 to 30,000 eggs. 
18. vi. 20. On the 7th day after infection all four pigs were seriously ill with pneumonic 
symptoms. Pig I died during the night, and larvae of A. suilla were found in enormous 
numbers in its trachea. 
26. vi. 20. On the 15th day after infection Pig II was killed. A. suilla larvae, 3-5 mm. 
in length, were found throughout the small intestine, on the average one specimen in every 
centimetre of gut examined. The mucosa was in a catarrhal condition. Caecum and rectum 
negative. 
28. vi. 20. On the 17th day after infection, Pig III was killed. A. suilla larvae, 4-7 mm. 
long, were found in its small intestine, one specimen in every 7 cm. of gut examined. 
30. vi. 20. On the 19th day after infection, Pig IV was killed. A. suilla larvae, 6-7 mm. 
long, were found in its small intestine, one specimen in every 8 cm. of gut examined. 
The foregoing experiments therefore resulted in the finding of larvae in 
the small intestine on the 15th, 17th and 19th days after infection. They had 
grown from 3 mm. on the 14th day to 7 mm. on the 19th. 
