58 TOILERS IN THE SEA, 



one-third of organisms in a cubic inch of chalk, and 

 this calculation is, without doubt, very nearly correct. 

 The block of chalk already referred to contained 

 about 216 cubic inches, and, according to Ehrenberg's 

 calculation, should contain 288 millions of shells. 

 The total, according to our own estimate, based upon 

 experiment, was 256 millions, these latter having been 

 made before we were acquainted with Ehrenberg's 

 figures. Two independent calculations, so nearly 

 alike, must be held to strengthen each other, and 

 seem sufficient to establish the fact that between one 

 million and a quarter and one million and a third of 

 foraminiferous shells are contained in each cubic inch 

 of Kentish chalk 



To convey some slight idea of the vast number of 

 these little shells in an ounce of chalk, let us suppose 

 for a moment that each shell was as large as the 

 shell of the common garden snail (for /it would 

 appear to be near that size when seen through a 

 moderately high power under the microscope). If 

 such were the case, and these shells were placed side 

 by side, then the half million of shells in one ounce 

 of chalk would form an unbroken line of twelve miles 

 in length. Or, if we take the whole of the shells 

 contained in the experimental block of 216 inches 

 (or six inches in diameter in each direction), and 

 reckon them after the same rate, at 128 millions, 

 then, on the supposition that each was of the size of 



