Schistosoma Japoxicum 



397 



193 (2153) 



The route of migration of schistosoma japonicum in the body 



of its final host. 



By HENRY EDMUND MELENEY and ERNEST CARROLL FAUST. 



[From the Parasitology Laboratory, Department of Pathology, 

 Peking Union Medical College, Peking, China.] 



It is well established that the cercarial form of Schistosoina 

 japonicum enters the mammalian host through the skin, and that 

 it passes by way of the blood vessels to the lungs. The route 

 taken by the worms from the lungs to the portal and mesenteric 

 veins where they grow to maturity, has been disputed by various 

 Japanese investigators. Xarabayashi 1 concluded that they go 

 mainly by way of the pleural cavity into the mediastinal tissues, 

 and thence through the diaphragm into the abdominal cavity and, 

 by direct penetration, enter the liver and portal vein. Sueyasu 2 

 claims that they pass from the pleural cavity directly through 

 the diaphragm and into the liver. Miyagawa and Takemoto 3 

 believe that most of the worms leave the lungs through the pul- 

 monary veins, pass through the aorta and mesenteric arteries 

 into the capillaries of the stomach and intestine and thence into 

 the portal veins. The method used by all these investigators 

 consisted of the examination of serial microscopic sections of 

 mice killed at various intervals after infection. 



Owing to the discrepancy of these findings we used somewhat 

 different methods in attacking this problem. A series of ten 

 rabbits was heavily infected' and one was killed on each of the 

 first ten days thereafter. The peritoneal and pleural cavities 

 were washed out, and the blood vessels of the lungs, liver, spleen, 

 gastro-intestinal tract and posterior extremities were irrigated 

 with saline-citrate solution. The popliteal lymph nodes, lungs 

 and liver were cut into fine pieces and washed. The fluids from 

 all these washings and irrigations were then examined for worms. 



1 Xarabayashi, H., Mitteil Med. Gescll. Kyoto, 1916, xiii, Xos. 2-3 

 (Japanese text). 



2 Sueyasu, Y., Kyoto Igdku Zassi, 1920, xvii, No. 1 (Japanese text with 

 German abstract). 



3 Miyagawa, Y., and Takemoto, S., Jour. Path, and Bact., 1921. xxvi, 168. 



