560 The Philippine Journal of Science 1922 
PATHOLOGY AND MORBID ANATOMY 
The morbid anatomy depends on the presence of both the 
adult parasite and the ovum, and on the extent of the changes 
in the fixed tissue in the organs where both parasite and ova 
have lodged as emboli. 
The penetration of the skin by the cercaria causes an intense 
erythema which was regarded by the Japanese workers as a 
skin disease and is called “kabure,” while the clinical symptoms 
were supposed to be a special disease known as “katamaya 
fever.” The evanescent urticarias, cedema, fever, and the 
cough and hemoptysis in the early morning with areas of pul- 
monary dullness in the first stage of the disease(18) point to 
the existence of toxin secreted by the parasite and inflamma- 
tion in the lungs due to its passage through this organ on its 
way to the intestinal circulation. 
The local necrosis of the cells in the bed of the ovum, and 
the cellular and fixed tissue reaction show not only that the 
ovum acts as a foreign body, but also that toxin is secreted 
by the contained miracidium. This necrosis may be circum- 
scribed, when it can be recognized only with the help of the 
microscope, or it may be large enough to be detected by the 
naked eye. It seems that a period of time is needed for this 
necrosis to develop, for in cases of hyperpyrexia, which hastens 
the dissemination of the ova, no necrosis is recognized around 
the freshly laid ova. It may be that the hyperpyrexia induces 
in the female parasite an early discharge of the ova, which, 
being immature, do not contain enough toxin to produce 
necrosis. 
The necrotic substance disappears later, either by absorption, 
by phagocytosis, or by breaking into a neighboring cavity or 
lumen with or without the help of pyogenic microédrganisms, 
and in this way the ova are discharged. 
It seems that the endothelial leucocytes are the first ones to 
respond; that they coalesce to form giant cells in case one or 
two of them cannot engulf or kill the miracidium inside the 
ovum; and that the fibroblasts and the eosinophilic and round- 
cell infiltrations come later. The histological picture is, there- 
fore, that of chronic productive inflammation. 
The adult parasite is supposed to live at least two years in 
the definitive host, and thus oviposition occurs not only once or 
twice, but many times. Each time the ova are disseminated, 
an inflammation takes place in the organs where they are de- 
