57 
But there is an animal very like a Mouse (the Lemming) which does 
make extensive burroxs's. It is provided wilh powerful sickle-shaped claws 
specially adapted for digging, and although I have not met with any account 
of the plan on which their burrows are constructed’), there is abundant 
evidence that they do make them. Captain Mc’ Glintock says in his diary 
of the expedition of the "Fox»: — «Hare-tracks are pretty common along 
the shore, and upon the sides of steep hiils; they make burrows under the 
snow, but we have never found them in the earth like those of the Fox 
and Lemming.« Von Baer says that in Nova Zembla gentie declivities are 
frequently burrowed through in every direction by them. In faet, the habit 
is notorious. ‘ 
Another point in favour of the Iceland animal being a Lemming is, 
that Olufsen speaks of it as often white. Now although the Mus sylvaticus 
sometimes may be found white, when such a thing oceurs it is only a 
case of albinism, and rare. But the Lemming in America is said regu- 
larly to become white in winter, although not so completely so as the 
Weasels. Both in Spitzbergen and Nova Zembla a little white animal has 
been observed. MM. Pachtissow and Ziwolka, during their winter stay in Nova 
Zembla, saw a little white animal in their hut which they, in their jour¬ 
nal, call a Mouse. According to Mr. Ziwolka it was larger thann a common 
domestic Mouse, and therefore could not have been a white individual of 
that species. It was doubtless a Lemming. According to Von Baer there 
are two species of Lemming found in Nova Zembla, one of w'hich he con- 
sidered identical with the Myodes Hudsonius. 
As the Lemming is an Arctic animal, it must pass a longer night 
of winter than ordinary torpidity could survive. Some arrangement for a 
winter supply is therefore plainly necessary, and it is scarcely possible to 
conceive anything better adapted to the purpose than that described by 
Henderson. 
1 have, therefore, no doubt in my own mind that the economic Mouse 
of Iceland is a Lemming; and as Greenland is the nearest point where 
Lemmings have been found, I think it a fair conjecture, until rebutted by 
direct evidence, that the species found there is the American Lemming 
Myodes Hudsonius.« 
’) John Wolley omtaler kun simple Gange i Græsset paa Jordover¬ 
fladen og Huller paa Siden af Tuerne, i hvilke de bosætte sig og uden¬ 
for hvilke Excremenlerne findes i store Dynger. Skand. Naturf. Mode 
1863. S. 217 o. tig. 
