576 ON THE QEOaRAPHICAL DISTRIBUTION 



as to Siberia ; neither MiddendorfF, nor Radde, nor the great Pallas, 

 treating as they do so exhaustively of the natural history of that 

 region, ever within my knowledge make any allusion to the exist- 

 ence there of Fasciola hepatica as a cause of sheep disease. As 

 regards, however, the existence of this animal and of the sheep-rot 

 in Greenland, as testified by Leuckart, I wish to lay alongside of it 

 the following statement from the English translation of Rink's 

 ' Greenland ' already referred to, and edited by Dr. Robert Brown 

 in 1877. There, p. 97, it is stated that about the year 1855 there 

 were in the whole of Greenland only from thirty to forty cows, a 

 hundred goats, and twenty sheep, and that this handful of cattle 

 were located at Julianshaab, on the west coast. A statement to 

 the same effect is given by Dr. Brown himself in the ' Manual of 

 Arctic Instruction,' 1875, p. 27. Surely if the rot still exists in 

 Greenland, and has not shared the fate of so many other forms of 

 life which have finally left its inhospitable shores, we have in 

 Julianshaab a simple case and a circumscribed area wherein to 

 prosecute research. 



If the presence oi Fasciola Jiepatica in an isolated locality — that of 

 Julianshaab, on the west coast of Greenland — is likely to prove 

 instructive, its absence from Iceland may also throw some light 

 upon the subject. Most or all of the moUusca which have been or 

 can be supposed to act and suffer as Zwischenwirth for the Fasciola 

 are to be found in Iceland, viz. Arion ater^ Arion hortemis, Limnaea 

 truncatula and Limnaea peregra ^, as well as Vlanorlis rotundatuSf if 

 not PlanorUs marginatus. And that abundant opportunities for the 

 introduction of Fasciola hepatica into Iceland have been given by 

 the importation of sheep from abroad is learnt from what Olafsen, 

 I.e., ii. pp. 198-199, tells us as to the ascription of another sort of 

 sheep disease to such importation. 



I incline to ascribe this immunity from rot which the sheep 

 enjoy in Iceland to the habit which they in common with the 

 Shetland and Orkney sheep have of feeding between high- and 

 low-water marks upon the sea-weeds specified by Olafsen in various 

 passages, q.v.. I.e., i. i'>,'^, 379, ii. 198, and Low, ' Domestic Animals 

 of Great Britain,' p. 59. The Fasciola Jiepatica is a freshwater 

 animal, and would not of course be picked up in such a locality as 

 the interval between ' Ebbe and Fluth,^ to which the sheep resort 

 ^ See Morch, 'Eaunula Molluscorum Islandiae,' 1868, pp. la and 16. 



