RUPTURE OF THE CYST INTO THE BLOOD-VESSELS. 649 



among the forty-three such cases cited by Neisser no fewer than 

 thirty-seven were cured, while in the cases where the contents were 

 evacuated by expectoration, only about three-fourths (twenty-three out 

 of thirty-one) recovered. From the intestine the expulsion of the 

 bladder contents is usually effected per anum, and only in the case 

 of ruptures situated high up per os. The expulsion is sometimes so 

 favourably accomplished that the hydatids reach the exterior un- 

 injured. Davaine mentions the case of a woman in Paris who was 

 thus suspected of laying eggs. In the majority of cases merely 

 membranous shreds are voided, and their true nature is sometimes 

 recognisable only by the help of the microscope. 



Besides the above-named organs, the blood-vessels sometimes 

 receive the contents of the burst Uchinococcus. This may happen, for 

 example, if the parasite have been developed in the cardiac muscles 

 and burst through the endocardium after a longer or shorter period of 

 inflammation. It may also occur in the liver or lungs, in which cases 

 the large vessels, and especially the veins, are affected by the worm 

 exactly as were the hepatic ducts or bronchiae. On the whole, such 

 cases are rare, and happily so, since they are almost always fatal either 

 gradually or more suddenly (by thrombosis). Professor Luschka had 

 the goodness to tell me of an interesting case of this sort, which I 

 note the more readily, since there are but few such observations 

 on record. It concerned a woman forty-five years old, who died 

 suddenly with symptoms of asphyxia, and yet without apparent cause. 

 On dissection the cause was revealed. In the region of the posterior 

 border of the liver there was an JEchinococcus about the size of a 

 child's head, which in the fossa venae cavae had broken through the 

 wall of that vessel, and there liberated its contents. The daughter- 

 bladders had reached the right chamber of the heart, and thence also 

 the pulmonary arteries, where they had induced an embolism which 

 rapidly caused death. When the obstruction of the pulmonary 

 arteries is incomplete, then, instead of sudden death, a more pro- 

 tracted disease ensues, that has essentially the same symptoms as 

 stenosis of the pulmonary artery, and, like it, is accompanied by 

 dilatation and hypertrophy of the right heart. 



The situation is very different when the daughter-bladders pass 

 through the pulmonary vein into the current of the aorta, and thence 

 into the peripheral vessels ; the result being that the portions robbed 

 of their blood supply mortify. 



The phenomena evoked by Echinococcus in brain or eye are like 



those occasioned by Cysticercus cellulosm. Their intensity is, indeed, 



greater, but that is sufficiently explained by the more prolonged and 



more vigorous growth of the worm. In the interior of the eye it has 



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