CHALK MAKERS, OR FORAMINIFERA. 55 



many more. Such immense numbers are outside 

 the range of our experience, and we can form no 

 conception of them. Suffice it to say that one ounce 



FIG. II. CHALK OF SICILY. 



would contain the shells of more animals than there 

 are human beings in the great metropolis of London. 

 But what an infinitesimal fraction this ounce would 

 be of the number of shells of these animals, living 



