32 The Bible of Nature 



a worm will turn." But we pause to think of the 

 part earthworms have played in the history of the 

 earth, and we recognize that they are the most use- 

 ful animals. By their burrowing they loosen the 

 earth, making way for the plant rootlets and the 

 raindrops; by bruising the soil in their gizzard they 

 reduce the mineral particles to more useful form; 

 by burying the surface with stuff brought up from 

 beneath they were ploughers before the plough, 

 and by burying leaves they have made a great part 

 of the vegetable mould over the whole earth. 

 There may be 50,000 or 500,000 of them in an 

 acre; they often pass ten tons of soil per acre per 

 annum through their bodies; and they cover the 

 surface at the rate of three inches in fifteen years. 

 We begin to respect them. 



We inquire into their structure — their ex- 

 quisitely sensitive skin, their highly developed 

 musculature arranged like the hoops and staves 

 of a barrel, their food canal — an object-lesson in 

 division of labor, their red blood — so different 

 from our own, their exquisite kidney-tubes, their 

 tiny brains and their ventral chain of nerve-centres, 

 we go into minutiae and we find that it will take 

 us many months to work out the details of the 

 nerve-cells or of the complex reproductive system. 

 The more we know, the more the wonder grows. 



We study their habits — their long nocturnal 

 peregrinations prompted by **love" and hunger, 



