by throwing together the returns of those four hospitals we 

 get an idea of twenty years of hospital work in Great Britain, 

 and they show that in all 110 cases of hydatids were under 

 treatment. During the same period there were about 99,000 

 in-patients, medical and surgical, treated, so that about one case 

 out of every 900 treated in these institutions during the periods 

 in question was one of hydatids. As far, then, as the data at 

 our disposal extend, we may conclude that about one death out 

 of every 12,000 in England and Wales during the decade 1871- 

 81 was due to hydatids, and that about one out of every 900 in- 

 patients of the four hospitals mentioned was a case of 

 hydatids. 



Geemaxt, Eeance, Italt, ArsxRiA, and Eussia. — As far as 

 I have been able to ascertain no data exist to show the 

 prevalence of hydatids in these countries. However, the 

 occurrence of the parasite in France, Germany, and Italy is 

 certain. 



Hydatid Disease ix Icela^s'd. — This country holds the 

 unenviable position of being the one most highly infested 

 with Echinococcus disease, and it may be instructive to 

 devote some attention to the matter. It appears certain that 

 hydatid disease has been just as prevalent in Iceland for cen- 

 turies past as it is at the present time, for the earliest medical 

 records of the country contain references to the prevalence of 

 an affection of the liver, which could have been nothing 

 other than this parasitic disease. Up to the present time 

 an exact estimate of the frequency of the disease cannot 

 be given, for the medical men resident in the country 

 do not agree as to the proportion of the population at- 

 tacked. Then, a great many persons have hydatids, and 

 yet die of some other complaint; moreover, post-mortem ex- 

 aminations are made comparatively rarely ; and, lastly, many 

 of the victims of the disease recover by the efforts of unaided 

 nature. However, many good authorities believe that from 

 one-fifth to one-seventh of the entire population of Iceland 

 suffers from hydatid disease. Other medical observers regard 

 this estimate as too high, and consider that from one-fiftieth to 

 one-sixtieth would be a more correct calculation. On the 

 whole it seems to me that the balance of evidence points in the 



direction of the hipjher rather than of the lower fio^ures. The 



. . . 



Danish Government was so impressed with the gravity and 



extent of the evil that in 1863 it deputed a distinguished hel- 



minthologist, M. Krabbe, to investigate and report upon this 



question, and the result of his inquiries appeared in a treatise 



published in 1866, written, fortunately for us, in Erench, and 



not in Danish. He points out that the prevalence of hydatids 



