9 
power and later under a higher power dry lens. It will not always be 
possible to determine from the microscopic examination alone whether 
the infection is hepatic or intestinal, as the size of the eggs varies and 
the exact species can not always be definitely determined from the egg. 
KEY TO TFTE EGGS OP TREMATODES REPORTED FOR MAN. 
(For species thus far found in the United States, follow Roman type.) 
1. Eggs in sputum; embryo not developed. Parasitic hemoptysis 2 
Eggs in feces; embryo developed or undeveloped 3 
Eggs in urine; 120 fi long by 50 broad; provided with a 20 /< long terminal 
or subterminal spine; contain no embryo when first oviposited, but 
embryo may develop before egg is discharged from the host. Bilhar- 
ziosis (Egyptian hematuria) Schistosoma hmnatobium (p. 50) 
2. Egg 68 to 118/^ long by 48 to 60 broad. This is the egg usually found in 
parasitic hemoptysis Paragonimus westermanii (p. 16) 
Egg 150 to 190 long by 75 to 90f.L broad. Very rare in man 
Fasciola gigantica (p. 19) 
EGGS IN FECES. 
3. The vsame egg also in the sputum 1 
The same egg may also be in the urine 1 
The same egg neither in the sputum nor in the urine 4 
4. Egg more than 100 /< long 5 
Egg less than 50 long 6 
5. Egg 130 to 145/1 long by 70 to 90/4 broad; does not contain embryo when 
discharged in feces. Indicates infection of the . .Fasciola hepatica (p. 22) 
Egg 120 to 130 p long by 77 p broad; does not contain embryo when discharged 
- in the feces. Indicates infection of the intestine Fasciolop)sis buskii (p. 41) 
Egg 150 p long by 80 p broad. Indicates inf ection of the intestine 
Fasciolopsis rathouisi (p. 42) 
Egg 150 p long by 72 p broad. Indiccdes infection of the intestine - 
Gastrodiscus hominis (p. 46) 
6. Egg contains embryo 7 
^Not stated vdiether egg contains embryo; egg 34 P long by 19 to 21 p broad. In- 
dicates inf ectioiv of the liver Opisthorchis noverca (p. 33) 
7. Embryo with tivo dark spots in posterior hcdf; egg dark, 38 to 45 p long by 22 
to 30 p broad. Indiccdes infection of the liver Dicrocoelium lanceatum (p. 29) 
Embryo without said spots 8 
8. Egg 26 to 30 u long by 11 to 15 p broad. Indiccdes infection of the liver 
Opisthorchis felineus (p. 31) 
Egg 28 to 30 p long by 16 to 17 p broad. Indicates infection of. the liver . . 
Opisthorchis sinensis (p. 35) 
Egg 20 to 30 p long by 15 to 17 p broad. Indiccdes infection of the intestine 
Heterophyes heterophyes (p. 45) 
THE PARASITES OF DISTOM ATOSIS. 
Except in cases of intestinal distomatosis and occasionally in hepatic 
infection, the physician will rarely, if ever, see the parasite during the 
life of his patient. If trematodes are found on autopsy, the}^ may be 
determined by use of the key given on p. 11. 
