' 



How Animals Work. 



northern parts of the Atlantic Ocean, as much as 97 per 

 cent, of the mud, or " ooze " as it is called, brought 

 up from these depths being entirely composed of its 

 minute shells. The living Globigerinae frequent the 

 surface waters of the sea, and their shells are bedecked 

 with innumerable delicate spines which extend radially 

 to a length equal to four or five times the diameter of 

 the shell, giving them a most striking appearance ; but 

 on the death of the animal, the shell, in its descent to 

 the great depth at which it at last reaches the floor 

 of the ocean, loses its armature of delicate spines, so 

 that only the tiny cluster of spheres remains. At these 

 great depths, on the floor of the Atlantic to-day, new 

 chalk is being formed in just the -same way as it was 

 at the bottom of the sea in past ages by the con- 

 stant accumulation of uncountable myriads of the re- 

 mains of these Foraminifera ; and in time to come 

 these consolidated remains may in all probability rise 

 above the surface of the sea to form dry land, in much 

 the same manner as the chalk cliffs and the North 

 and South Downs of England rose from out the sea 

 in the long past. Even without the true knowledge of 

 how they were formed, it is impossible to stand at the 

 base of the towering, majestic white cliffs without feeling 

 a thrill of admiration for their grandeur and beauty, at 

 the absolute perfection of Nature's handiwork; and when 

 we try to realize how they were gradually formed beneath 

 the waters of the ocean, beneath the " stillness of the 

 central sea," slowly, surely, perfectly through the long 

 ages, until in the fullness of time they rose above the 

 surface, monuments built from the accumulated remains 

 of the infinitely minute, how truly glorious and awe- 



