LEMMING MIGRATIONS 
be, regardless of how the valleys trend, climbing a mountain 
instead of going around it, and, undeterred by any river or lake 
keep persistently onward until finally some survivors reach 
the sea, into which they plunge and perish. The Norwegian 
peasants have many superstitions relating to these migrations, 
and will assure you that the lemmings rain down. Almost as 
illogical is the theory formerly held by the learned that these 
movements are prompted by an ancient instinct which forces 
the animals to seek, at times, a mythical land of plenty, — an 
Atlantis, — now submerged in the ocean, whence their ances- 
tors came ages ago. It is more rational to suppose that under 
specially favorable conditions the lemmings multiply so fast 
that their natural habitat in the high central moun- 
tains fails to supply sufficient food, and thus a move- ming Mi- 
ment outward from that center begins. As the lem- 
mings reach cultivated ground, the abundance of food and a 
warmer climate lead to a marked increase, and as the females 
when only six months old bear young, and then produce several 
litters annually, their number soon becomes countless, and the 
swarm must spread. This leaves unaccounted for their in- 
veterate attempt to reach the sea. It is plain that the ancient 
notion that they go under a mysterious impulse to commit 
suicide, is absurd. Their impulse is simply to keep going, — 
why always straight east or west, we cannot say; probably 
simply because the valleys and dip of the land is in that direc- 
tion. Certainly there is no reason to believe that they know 
or care anything about the ocean at all; and the truth prob- 
ably is, that when they come to the strand they enter the water 
with no idea of its breadth or depth. 
“They descend from the Kolen [Mountains], marching in parallel lines 
three feet apart; they traverse Nordland and Finmark, cross lakes and 
rivers, and gnaw through hay and corn stacks rather than go round. They 
infect the ground, and the cattle perish which taste of the grass they have 
touched; nothing stops them, neither fire, torrents, lakes, nor morasses. 
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