LEAF AND TENDRIL 



certain habit, no matter how many times defeated. 

 This plant forms a new bulb each spring by sending 

 out a big tap-root, that bores down into the ground 

 and plants the new bulb deeper and deeper each 

 season till the required depth of six or eight inches 

 is reached. When the ground is so hard that the 

 pioneer root cannot penetrate it, it wanders in loops 

 over the surface and forms the new bulb no deeper 

 than the old one was, and keeps this habit up 

 spring after spring, groping its way blindly about 

 over the hard surface. 



As further illustration of the automatic character 

 of animal instinct, take the case of the migrating 

 lemmings in Norway and Sweden. At times the 

 country gets overstocked with these rodents, when 

 vast numbers of them migrate down from the hills 

 toward the sea, swimming the lakes and rivers in 

 their way. This seems a reasonable course, and is 

 very much what men would do under like circum- 

 stances; their instincts accord with reason. But 

 mark what follows: when the lemmings reach the 

 sea, they plunge in and swim till they perish. Hav- 

 ing got in motion, they go on, like any other natural 

 force, till they have spent themselves. It is said that 

 steamships have at times encountered these bands 

 of swimming rodents and been half an hour in 

 steaming through them. I do not suppose they 

 mistake the sea for another lake or river such as they 

 have already crossed ; I do not suppose any notions 

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