THE NORWEGIAN LEMMING. 



411 



few individuals have preceded the main body, and that during the 

 first autumn the numbers are never large, but, after a winter spent be- 

 neath the snow, they begin to breed with the first days of summer, 

 and thus develop the extraordinary multitude which is, as it well may 

 be, the astonishment and terror of the country. It appears, then, that 

 excessive reproduction is rather the result than the cause of migra- 

 tion. It has also been suggested that the course taken by the lem- 

 mings follows the natural declivities of the country, but a reference to 

 the maps will show that in that case nearly all the Norwegian migra- 

 tions should take a sovitherly route, which is by no means the case. 

 On the contrary, westward at lieimdalen means across a rapid river, 

 over a wide lake, and up a steep, rocky, and snowy mountain, and 

 this is the course which is followed. Now, this ends eventually in the 

 ocean, and thus we are again landed at the question from which we 

 set out. After all, it is not the power of direction which is so remark- 

 able ; this is a faculty possessed by many animals, and by man him- 

 self in a savage state. A young dog which I took from England, and 

 then from my home in Yaage by a path to Heimdalen, a distance of 

 forty-six miles, ran back the next morning by a direct route of his 

 own, crossing three rapid rivers and much snow, and accomplishing the 

 distance in six hours, without the vestige of a path. This same dog 

 afterward repeated the feat, but followed the path, and took two days 

 in reaching his destination, hindered and not aided, as I believe, by 

 his experience. Herr Palmen, indeed, says, " Experience guides mi- 

 gration, and the older migrants guide the younger," like one of Mr. 

 Cook's personally-conducted tours. This obviously cannot be the 

 case with the lemmings. 



It is now generally admitted that instinct is merely inherited ex- 

 perience, and is, therefore, primarily calculated to benefit the species, 

 unless, indeed, circumstances have changed meanwhile more rapidly 

 than the structures to which the phenomena of instinct are due. Now, 

 the lemmings during their wanderings pass through a land of milk 

 and honey, where, if their instincts could be appeased, they might 

 well take up a permanent abode ; and yet they pass on, while their 

 congener, the field-vole, remains in quiet possession of the quarters 

 from which he was temporarily ousted. It is, indeed, almost as 

 strange a sight to see the holes, the deeply-grooved runs, and the 

 heaps of refuse, of these restless creatures, which have passed away 

 but yesterday, as it is to see the fjelds suddenly become alive with a 

 new and boisterous tenant, who, like another Ishmael, has the hand 

 of all men against him. 



Now, if we compare the migration of the lemmings with that of 

 our more familiar swallows, we find that the latter obviously seek a 

 more genial climate and more abundant food, returning to us as surely 

 as summer itself; nor do they ever, so far as I know, breed on their 

 passage. The swifts, which stay but a short time with us, remain in 



