HYDATID DISEASE OF ICELAND. 233 



APPENDIX. 



REFLECTIONS ON THE PRODUCTION OF THE HYDATID DISEASE 

 ENDEMIC IN ICELAND, IN AS FAR AS IT IS CAUSED BY 

 ECHINOCOCCI. 



When we find that the Echinococci, and especially Echinoc. 

 altricipariens, are an endemic disease in Iceland, and from the 

 travels of Von Troil, and the " Voyage en Islande, fait par ordre de 

 S. M. Danoise, traduit par Gauthier de Lapeyronie," that a sort of 

 vertigo (Hoved Soften) occurs there endemically in sheep 1 and 

 cattle, which is curable by the trocar, on the employment of 

 which a watery fluid is evacuated from the brain, it is very 

 evident that Coenuri are not of rare occurrence in Iceland, 

 and that they are a great plague to breeders of cattle, and we 

 must conclude that Iceland is a land which presents a more 

 favorable soil for the development of the cystic worms in general 

 than many other countries. From analogy we may assume that one 

 reason of this lies in the fact, that the places where these cystic 

 worms are particularly plentiful, that is to say, the districts in the 

 interior, must be humid, as it is well known that Coenuri rarely 

 thrive in dry districts. The numerous hot wells in those 

 districts of the interior of Iceland favour the production of 

 this humidity of the soil, in part directly, by the water flowing 

 from them, and in part from the vapours which rise from them 

 into the air in considerable quantity. In this, therefore, we 

 have a confirmation of the general observation as to the production 



1 The Icelandic sheep have pointed ears and a short tail ; sometimes they have two, 

 three, or four horns, which are sometimes straight, sometimes bent forwards, and some- 

 times backwards, and sometimes no horns. One animal gives four pounds of wool, 

 which falls off in the spring without shearing. 



