Parasites of the Spleen. 369 



On the other hand, the lungs of hogs are usually tanked, and 

 minute lesions are not looked for, so that the lack of cases cannot 

 be held to positively imply their absence, but rather the infre- 

 quency of aggravated and easily recognized cases. Dr. Payne 

 failed to trace the affected hogs to the districts or farms that fur- 

 nished them, so that the probable original source of the parasite 

 and its relation to the possible implication of man or other ani- 

 mals in the infested localities, remain in obscurity. 



The facts, however, bear out these conclusions : ist. That 

 the Paragonimus, whatever its original source, Asiatic or indige- 

 nous, has already gained a considerable foothold in swine in 

 some localities in the United States. 2nd. From the lack of re- 

 corded cases oi parasitic hcsmoptysis in America, there is a strong 

 probabilitj' that the infected areas supplying the diseased hogs, 

 have not been infested for an indefinite period, but only for a 

 short time, and that the parasites have been presumably brought 

 by people coming from Asia. 3rd. That the Paragonimus has 

 found in certain districts in America the conditions, including the 

 hypothetical intermediate host, requisite to its permanence and 

 extension. 4th. That sanitary considerations demand the tracing 

 out of infested areas, the suppression of the affection, the seclu- 

 sion or safe disposal of all infested subjects, and rigorous super- 

 vision of all arrivals of men or animals from the infested east. 



The lesions found in the lungs of hogs closely agreed with those 

 of the tiger ; almost every cyst enclosed two worms — only on rare 

 occasions would a cyst contain one or three. The cysts were 

 from 12 to 36 mm. in diameter, and contained a semi-fluid, choc- 

 olate colored matter containing numerous ova. Sometimes two 

 adjacent cysts communicated. The cysts were mostly on or near 

 the surface of the lungs, but a number were deeply imbedded in 

 the lung substance. 



The Paragonimus obtained from American hogs averaged 

 somewhat larger than the specimens from dogs or human beings 

 in Japan, but the general characters were essentially the same. 

 There is no good reason for supposing them to be specifically 

 distinct. 



Symptoms axe lacking, as the worms were only found post- 

 mortem in hogs in good enough condition to be killed for pork. 

 The good condition of the hosts is again in perfect keeping with 

 24 



