390 PARASITIC ANIMALS IN CATTLE. 



mules, are occasionally found with them also, as well as 

 rats, mice, &c. ; but in sheep, goats, and deer, they are 

 common. Yet what connexion the animal has with dis- 

 ease is involved in much obscurity : certain it is, however, 

 that both rot, and the vast increase of the fluke, are con- 

 nected with a moist state of the pasturage. Salt marshes 

 never produce it ; and salt is supposed to be a remedy in 

 the early stages. It seldom attacks sheep on high grounds ; 

 but the sheep having once received the infection, of what- 

 ever nature it may be, removal to another pasture is then 

 almost too late. 



Hydatids, as producing what is known as staggers, or 

 turnsick, in sheep, are less common but sufficiently fatal. 

 This vesicular animal, which is found within the cerebral 

 cavities, produces effects which have received various pro- 

 vincial but characteristic names, being called gid, starers, 

 goggles, sturdy, &c. They are universal throughout Europe, 

 and, indeed, infest the flocks of most quarters of the globe. 

 Hydatids also make their way, now and then, into the 

 spinal canal, when they occasion paralysis. The vitality of 

 the tanius globuleux or ccenurus cerehralis is fully evinced on 

 being put into water, which, if it be warm, excites lively 

 motions in the animal, whose size varies from that of a 

 pigeon's egg to the minutest vesicle. They are found 

 sometimes solitary, and at others two or three are placed 

 together wuthin the ventricles of the brain ; occasionally 

 they are discovered within the substance of the cerebellum ; 

 but more frequently immediately on the surface of the 

 cerebral hemispheres : and it is said they are more common 

 to the right lobe than to the left ; their effects are gene- 

 rally produced on the opposite side to that on which the 

 parasitic animal is situated ; it is usual to find the hy- 

 datid on that side of the head towards which the sheep 

 inclines in his revolutionary gait. When this disease has 

 existed some time, the ravages it occasions are very great : 

 one of the cerebral lobes has been found almost destroyed ; 

 one of the ventricles has been distended to ten times its 

 original magnitude : while in other instances, one of the 

 parietal bones has become so absorbed by the pressure of 

 the hydatid, when situated on the cerebral suiface, as 

 scarcely to offer the smallest resistance to the touch. It is 



