DISEASES OF THE LIVER. r.)f 



developing nicany new embryos within it ; these embryos may 

 form new brood capsules and thus increase their numbers 

 materially, or if swallowed by a mammal along with its food or 

 water they develop into the mature flukes, inhabiting the Dile 

 ducts and reproducing themselves only by eggs. The necessity 

 for these intermediate generations, and the fact that they can 

 only take place in fresh water and in fresh water moUusks, 

 points to thorough dramage as the most efficient means of 

 limiting the ravages of the parasites. 



In small numbers they do little harm, and as they cannot 

 multiply within the body their presence may be of no conse- 

 quence, but when present in large numbers they become most 

 destructive. In certain damp lands stocked with these parasites 

 sheep cannot live, no matter how well fed, and cattle often 

 perish as well. A single infected sheep brought on such damp 

 lands will speedily stock them, as infested German rams did the 

 colony of Victoria in 1855. 



Symptoms. — Sheep may thrive unusually for a Month or two, 

 but soon they begin to lose flesh and waste with a rapidity that 

 is surprising. The skin and the membranes of the nose and 

 eyes become soft and puffy, the naturally bright pink vessels of 

 the eye become yellowish, dark, or even quite imperceptible, 

 the whole eye assumes a yellow tinge, the skin is pale, bloodless, 

 deficient in yolk or oil, dry and scurfy. The wool loses its 

 brilliancy and comes out easily when pulled. The muscles 

 waste, the animal is razor -backed, the hip-bones i)roject, and the 

 flank becomes sunken, the belly pendent, and the back drooped 

 from dropsical eff"usion. Similar effusions take place in the 

 chest beneath the abdomen and breast-bone and under the 

 lower jaw. The head is no longer carried erect, the expression 

 of the face is haggard and hopeless, the appetite capricious, 

 thirst ardent, anc'i there is occasional diarrhoea. Examination 

 of the dung detects myriads of microscopic eggs y^ inch in 

 'liamelcr. 



