THE NUMBERS OF FORAMINIFERA FOUND IN CHALK. 151 



yj^j of an inch, it would require nearly ten millions placed end to 

 end to reach a mile. Taking this, then, as the basis of our calcula- 

 tions, we shall find that our Kentish firm have dug from this chalk 

 pit Foraminifera sufficient, minute as they are, to extend for, at the 

 least, 1,006,915,840 miles. From one chalk pit, out of many 

 hundreds in active operation, one manufacturer of lime and cement 

 has, within about a quarter of a century, dug out the shells of 

 these minute animals, each one of which is nearly invisible to 

 the naked eye, in sufficient quantity to reach more than a thousand 

 millions of miles, adopting a moderate calculation ; yet even this 

 is a number more vast than our minds can grasp — what therefore 

 must be the number included in the white cliffs of Dover — in all 

 the chalk beds of Kent and Sussex ? 



