SCHISTOSOMA JAPONICUM 



279 



contoured. In faeces the eggs measure 83-5/1- by 62-5 //, (man); 85/4 

 by 61-5 fi (cattle) ; 98-2 //, by 73-8 p (dog). The eggs have either 

 small lateral spines or thickenings, and Looss at the opposite 

 side has described cap-like thickenings. 

 The eggs in the tissues undergo various de- 

 formities, and may contain a miracidium, as 

 also the eggs in fasces do ; or the contents 

 may consist of granular matter or amorphous 

 masses or they may be calcified. Lympho- 

 cytes and giant cells may also invade the 

 eggs. 



Mode of Infection. The miracidia hatch 

 in water in as little as fifteen minutes, but 

 the majority in one to three hours. They will live in water for about 

 twenty-four hours. In water they undergo a transformation into 

 " larvae/' which then penetrate the skin, as has been shown by 



FIG. 177 . Schistosoma japo- 

 nicum, male and female in co- 

 pula, x 60. (After Katsurada.) 



FIG. 178. Schistosoma japonicum : eggs from human liver, showing "spines" and 

 "hoods" at opposite pole. (After Looss.) 



Japanese writers to hold good for man, cattle, dog and cat. The 

 penetration of the skin is attended with an eruption on the legs, 

 " Kabure." The exact route by which the worms reach the portal vein 

 is uncertain. Infection in Japan takes place from spring to autumn, 

 especially May to July, when the soil is contaminated with manure 

 of cattle infected with S. japonicum. They also appear to develop 

 in molluscs. Leiper and Atkinson found cercariae (in sporocysts) 



