DISEASES OF SHEEP. 65 



describes a circle, of larger or smaller dimensions according 

 to the progress and state of thg disease (a straight gait 

 being a very seldom occurrence), the animal lifting its feet 

 very high and running against everything. The stupefac- 

 tion and senseless state increases by degrees, the animal 

 then being unable to seek its food, eating very little, and only 

 when food is forced into its mouth ; and even in such a case 

 the chewing is often interrupted, as if the animal forgets 

 eating such food. Finally, the lamb ceases eating entirely, 

 being unable to stand, laying its head sideways, and re- 

 maining in a perfect stupor and without motion until death 

 occurs sooner or later — often in a few weeks after the be- 

 ginning of the disease. When the disease has arrived at 

 an advanced degree, a soft place may be detected upon the 

 skull by pressing the same with the thumbs of both hands. 

 Here the so-called worm-bladder has its location ; this 

 worm-bladder presses the skull-bone, reduces its thickness, 

 and produces the very incidents of the disease, according to 

 the size, position and extent of such bla4der. The move- 

 ments of the sheep are directed sideways from the direction 

 where such bladder is situated, except when the bladder is 

 located upon the back part of the brain ; in such case the 

 animal moves with nose erect in a nearly straight line ; and 

 if the bladder is located upon the lower part of the brain, 

 the animal droops its head as low as possible. When such 

 a diseased animal is dissected, one or more of the before- 

 mentioned worm-bladders are found in the hollow part of 

 the skull. This bladder consists of a thin, closely-con- 

 structed membrane, filled with clear, light, yellowish, watery 

 fluid, in which a large number — often several hundred — of 

 small white corpuscles are observed, which appear to the 

 naked eye like poppy-seed ; when such a bladder and its cor- 

 puscles are examined by means of a magnifying glass, the 

 latter are found to consist of live animals of an oblong, 



