474 THE DISEASES AND DISORDERS OE THE OX. 



Stands apart from the rest of the flock, and often near water, 

 loses flesh, becomes emaciated, staggers in its walk, shows signs 

 of partial paralysis, for example by its awkward gait, the back 

 is stiff", the pupils ot the eyes are dilated, the conjunctiva has a 

 bluish tinge, and the eyeball itself is prominent. The sheep 

 may become quite blind, entirely lose its appetite, be altogether 

 unable to follow the flock, run up against trees, walls, or other 

 obstacles, and frequently turn round, usually in one direction, 

 and frequently towards the side opposite to that of the hemi- 

 sphere which is affected, for example to the right, if the hydatid 

 is situated on the left side, and vice versa. Moreover, if the 

 cyst lies between the two cerebral hemispheres, in the middle 

 line, so as in fact to correspond with a line passing through the 

 centre of the forehead, the animal will move more or less 

 persistently forwards in a straight direction, and run against a 

 wall or fence, or perhaps fall into a pond or ditch or river, as 

 the case may be, and be totally devoid of the power of extri- 

 cating itself from its perilous position. 



iVgain, in case the cyst is located in the cerebellum, the sheep 

 will lose control over the voluntary muscles and the limbs, which 

 will probably be lifted up in a peculiar, jerking kind of way, 

 and then put down again in an uncertain manner and without 

 precision and accuracy. In fact the animal may be observed to 

 advance with its head raised, and with a hesitating movement 

 of all its legs, and a special inability to lift up its fore-limbs. 

 Consequently the poor creature, in its bewilderment and dismay, 

 will probably try to advance by a succession of leaps ; but this 

 device only leads to it falling down in helpless incapacity, and 

 then to vain struggles and eff'orts to rise up again, and rollings 

 on its side. Moreover, in some cases, cysts may be present on 

 both sides of the brain, and if this is the case, the sheep thus 

 afflicted may turn now to the right side, now to the left. Of 

 course, in proportion to the growth of the hydatid, the number 

 of heads augments, the malady becomes more severe, the attacks 

 of giddiness and the running round and round in circles 

 become more extremely marked and more frequent, the rapidity 

 of the movements increases, and at length the animal becomes, 

 completely paralysed, and can no longer even stand. 



As for the cyst itself, it is in reality a bladder which is pro- 

 vided with a variable number of exsertile heads, and, according 



