MICRO-MAN 41 



in function and activity, almost as much, one might say, as 

 our gross animal world. Among them, if we may give fancy 

 a rein, we might imagine elephants and dogs, horses and 

 hippopotami, and all sorts of others. And we now know that 

 they are numbered like the leaves of the forest. The large 

 intestine of a man, for example, contains, normally, a bacterial 

 population perhaps a hundred thousand times the human 

 population of the earth say a hundred to one hundred and 

 fifty billions. 



For the moment we will endow this microbe with a brain, 

 though doubtless he possesses none ; such vague sensations as 

 he has he experiences, probably, with his whole being. We 

 will give him hands to grasp with, feet to travel on ; imagine 

 him like a man, infinitely curious, but soon tired ; able to go 

 but a very little way when he must lay his head against the 

 earth and sleep. 



This being I will conceive in precisely the same habitat as 

 that of man, as that of our own : I mean upon the fly-wheel 

 of an engine upon the surface of a very smooth and polished 

 fly-wheel, turning at 4000 or 5000 revolutions per minute. It is 

 little that we commonly think of our earth in such a guise ; but 

 equally little that we ever think of ourselves as one eight- 

 millionth part of the diameter of the earth. We are insensible 

 to the prodigious spin of the globe ; equally so, let us say, is 

 a bacillus upon a top. A wheel corresponding in size to this 

 microbe as the earth to man would be of course about five or 

 six feet in diameter ; but there is no fly-wheel as large as this 

 which turns at such a speed. The fly-wheel of a motor-car 

 the most familiar example one may choose nowadays makes 

 from 500 to 1500 revolutions ; and it is quite impossible to see 

 anything on its surface even at the slower speed. 



Whirling at such a velocity, the first thought of course 

 is that this microbe would be instantly swept off the wheel. 

 There is no need of alarm ; he is peacefully roaming about in 

 the plains and the valleys that extend all over the wheel, for 

 looked at under the microscope the surface of the wheel, polish 

 it as highly as we may, is still mount ainously " scarred and 

 thunder-riven." 



And does any one conceive that the smooth surface of the 

 fly-wheel does not answer to the rugged face of the earth ? 

 Let him then compute our highest Alpine or Himalayan 



