Liver Fluke of Sheep. 
93 
while it is well that such preventive measures as can be, 
should be taken in the course of good husbandry. 
The accompanying illustrations (Figs. 8 to 14), reproduced 
from Mr. Thomas’s articles, indicate the series of changes from 
deposition of the fluke egg. It will be seen that the egg must 
get into water and there develop into an embryo capable of 
boring into the body of a snail. This snail lives only in fresh 
FIG. 13.— An adult Fluke, showing the 
branched Digestive Tract. 
y, the oral ; y‘, the ventral sucker ; in, 
the branched intestine. In the centre, 
between the two main branches of the 
intestine, lies the chief trunk of the water- 
vessel. Twice the natural size. (Original. 
— W.H.J.) 
FIG. 14.— Another view of an adult Fluke 
showing the Reproductive Organs. 
y, the oral ; y \ the ventral sucker ; Od, 
the oviduct ; Ov, the ovary ; Vt, the vitel- 
larium or gland that forms the granular 
yolk-cells surrounding the embryo in the 
egg; Te, the anterior; Te‘, the posterior 
testis ; their ducts run forwards. The 
generative opening is in front of the 
ventral sucker. Twice the natural size. 
(Original. — W.H.J.) 
and not in salt water. In the body of the snail, the embryo 
develops, in three generations, many more, each of which 
passes out of the snail, and if taken in by the sheep with its 
food or water, becomes the sexually mature hermaphrodite 
fluke. The parasite having gained the liver of its host defies 
removal by any known means. 
