THE JERSEY VOLE. 5 



in the minimum of h.b. and tail. For comparison I have added 

 a table of measurements of the Common Bank-Vole. (All 

 measurements in millimetres) : — 



Evotoniys ccesarius. 



H.B. TAIL. H. F. EAR. 



Maximum. ..104 (120) 51(54) 18(21) 11 (12-5) 



Minimum... 94 (91) 45(41) 17(17*5) 10(10-5) 



Evotoniys glareolus. 



H. B. TAIL. H. F. EAR. 



Maximum 96 46 17 12 



Minimum 82 40 16 ..10 



To summarise the interesting points of the Jersey Vole, it 

 should be specially noted that we have here an animal enjoying 

 a much milder and more sunny climate than that of England, yet 

 in spite of this having the appearance of and being allied to Voles 

 of a colder climate than that of Britain on the whole. Students of 

 evolution have here an interesting problem as to the origin of 

 this Vole. It may be that the Jersey Vole is the descendant of 

 a race of Voles that migrated south (in the same way that 

 Lemmings of to-day migrate) when Jersey was connected with 

 the mainland. Query : Are the Voles aberrant descendants of a 

 Lemming-like ancestor ?* No definite conclusion can be gained 

 until a careful and thorough study is made of the Continental 

 Voles. At present the Jersey Vole is only known from the 

 island whose name it bears. It may therefore be found on the 

 mainland. I am strongly inclined to think that the Skomer 

 Vole {E. skomerensis) will one day be found occurring on the 

 mainland of Wales (c/. Zool. 1907, p. 302). 



If we do eventually discover the Jersey Vole or its prototype 

 in Continental Europe, its range can then be worked out, and its 

 limit may extend to the habitat of the northern Voles, to which, 

 as Mr. Miller says, it is allied. 



The next interesting feature is the dark colour of the Jersey 

 Vole. Many insular forms of both mammals and birds exhibit 

 this characteristic feature, as, for example, the dark Song- 



* Barrett-Hamilton (P. Z. S., May 19tli, 1896, p. 602) says :— " Mr, Bon- 

 hote informs me that the Norway Voles were very Lemming-like in appear- 

 ance when alive, and he found them inhabiting the same burrows as Lem* 

 mings." 



