. Fig. 4.—Upper Surface of the Brain showing at («) the Coenurus cere bralis cyst. Avonn are contained, on the substance of the brain, causes this special result. The sheep turns round and round in small circles, staggers, trembles, stops eating and drinking, is convulsed and finally dies of paralysis or exhaustion. If the head is examined there will be found these cysts, draAvings of which are taken from Cobbold's Treatise on Internal Parasites. These may contain many of the immature worms, scores or hundreds, attached to the inner surface of the bladder. It is the pressure of these watery bl
. Fig. 4.—Upper Surface of the Brain showing at («) the Coenurus cere bralis cyst. Avonn are contained, on the substance of the brain, causes this special result. The sheep turns round and round in small circles, staggers, trembles, stops eating and drinking, is convulsed and finally dies of paralysis or exhaustion. If the head is examined there will be found these cysts, draAvings of which are taken from Cobbold's Treatise on Internal Parasites. These may contain many of the immature worms, scores or hundreds, attached to the inner surface of the bladder. It is the pressure of these watery bladders, on the substance of the brain, by which the movements of the sheep are caused. Sheep become infected through the pasture on w'hich they feed, and on which the eggs •of the worm nuay have been dropped by dogs in their dung, or fi'om water in which the eggs may have been washed or deposited in any of the many ways possible. These eggs are taken of course into the sheep's stomach, and there hatching, they make their way bj- migration into several parts of the body, the eggs doubtless gaining access to the veins are thus distributed, but perish wherever deposited, except in the brain. Once there, the womis begin a migratory expedition in search of a resting place, making galleries through the brain substance, until they grow too large, when they form a large cyst or bladder in which they remain as above mentiond. In , the sheep so infested dies, or is slaughtered, when the head, thrown to the dogs, is eaten and these embryos ar swallowed. The history of the woniis described in the preceding pages is then repeated, and the segment or eggs of them mature in the in- testines of the dog until they are discharged and are taken once more into the sheep. In this larval stage the worm is known as Coenurus cere- bralis. After its first introduction into the brain of its host, it is about as large as a mustard seed, and the disease becomes manifest in five or six
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectsheep, bookyear1900
