404 



l^rjochow- Insel (70" n. Bi*.) in einem Exemplar gefunden.« }>ut 

 pei: c o n t r a im Amurland S e h r e n k tells us, I.e., that Limax agrestis 

 outnumbers Arion hortensis^ just as Avion hortensis outnumbers Limax 

 agrestis in Sweden, Finland and Lapland, and that while Limax agrestis 

 spreads into Spain, Portugal, Italy, Algeria and the Southern slopes of 

 the Caucasus, Arion hortensis reaches no further than the southern 

 slopes of the Pyrenees and Alps. 



In a letter published in the Times of April 14th, 1880 and repub- 

 lished with some omissions in the Zoologischer Anzeiger of May 24th, 

 p. 528 — 560, I suggested ÛiZit Arion ater may be the » Z wischen- 

 w i r t h « or one » Z w i s c h e n w i r t h « to Fasciola hepatica. For calling 

 the small black slug, upon the distribution of which I have, following 

 Schrenk and Middendorff, just been writing, ^i Arion aten^ I 

 have the example and authority of Forbes and Stanley and I think 

 that of Gerstfeldt. But now, following Schrenk more closely, I 

 should call it Arion hortensis and should wish to be understood to be of 

 opinion that it will, as I hope, by means of experiments now being 

 carried on in my laboratory by Mr. A. P. Thomas, be ultimately 

 shewn that the smaller of our two British Arions really is one at least 

 of the hosts infested by the Sheep fluke Fasciola hepatica. 



As regards the distribution of the Fasciola hepatica in Northern 

 regions we have the authority of Leuckart. »Die menschlichen 

 Parasiten«, I. 1863. p. 531 for saying that it is found in Greenland and 

 North America, and the same excellent authority quotes 1. c. II. 1876. 

 p. 870 Krabbe to the eff'ect that it is not found in Iceland. The last 

 statement is confirmed by Johnson in »Deutsche Zeitschrift für Thier- 

 medicin und vergleichende Pathologie, Bd. V. Heft 6. 1879. p. 413 in 

 the words »Leberegel kommen in Island nicht vor«. I wish to add that 

 there is no mention of the disease which Fasciola hepatica causes in 

 Olafs en's and Po v els en's two volumes of Travels in Iceland, 

 though the diseases of sheep are repeatedly treated of by those authors 

 (see German Translation published in 1774. I. p. 112, 280. II. p. 46, 

 198, 199). And a similar remark may be made as to Siberia: neither 

 Middendorff, nor Rad de, nor the great Pallas, treating as they 

 do so exhaustively of the Natural History ofthat region, even within iriy 

 knowledge make any allusion to the existence there of Fasciola hepa- 

 tica as a cause of Sheep disease. 



As regards however the existence of this animal and of the Shee}) 

 Rot in Greenland as testified to 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 



