358 MUSCARDINID^— MUSCARDINUS 



especial interest, because it yields to Winlaton Mills, Durham, by a few 

 miles only in respect of being the most northerly situation in England 

 where the Dormouse has been noticed. 



The only islands in which the Dormouse is known are Anglesey 

 (Forrest) and the Isle of Wight. 



Since it has been found within a few miles of the Borders, there 

 seems no reason why it should not occur in Scotland. But, although 

 there are a few old records, e.g., for Gifford, East Lothian (Mac- 

 Gillivray); Careston, Forfar {New Statist. Account, Forfarshire, 523); 

 and for Scotland without locality (Walker; Fleming), Alston was 

 unsuccessful in obtaining confirmation of them, and modern Scottish 

 naturalists are unable to give the animal a place in their fauna. 



The Dormouse is quite unknown in Ireland. Barrington set six 

 free at Fassaroe, Co. Wicklow, on 13th November 1885 {Zoologist, 1885, 

 479), but, as he informs me, they were never heard of again. The 

 season of introduction was not very well timed, since the animals 

 would probably, in a state of nature, have already commenced 

 hibernation. 



[Jonston, Historia Animalium, 1650-53, i., 163-64, mentions its 

 absence from Ireland, and its inability to live elsewhere in houses built 

 of Irish oak. Rutty (1772) brands Jonston's statement as a "vulgar 

 error," but though he rightly describes the animal's colour, he confuses 

 its nest with that of the Harvest Mouse, and his statement that it occurs 

 in Ireland shows that he could not have been himself acquainted with it.] 



Distribution in time : — This species is not known as a fossil in 

 Britain. 



Origin: — The absence of the Dormouse from Scotland, as well as 

 from the hiemally coldest part of the eastern plain of England, 

 suggests at first sight that winter cold is the governing factor in its 

 British distribution. But that is not the case, for in the greater 

 part of its continental range it is subjected to winter temperatures 

 lower than any experienced in the British Isles. Since the eastern 

 plain is the driest part of England, humidity is also ruled out. 

 The summer temperatures may next be considered. That of Norfolk 

 in July, is about 62 F. that of the south-east of Ireland about 6o° F., 

 but since the extreme northern limits of the animal's range, both 

 in Britain and Sweden, lie somewhere near the July isotherms of 

 6o° F. and 59° F., deficiency of summer heat cannot have caused the 

 absence of dormice from East Anglia and Ireland. Further, since the 

 next coldest July isotherm, that of 58 F., passes through Scotland 

 some distance north of that of 59 F., the gradient between the two 

 being shallow, it would seem quite possible that there are a number 

 of localities suitable for dormice in the south of Scotland, where the 

 hazel is abundant ; so that climatic conditions can hardly have caused 



