THE CLIFFS AND THEIR STORY 



297 



and beautiful group of tiny organisms 

 called the Foramcnifcrcc — microscopic 

 creatures with perforated shells. The 

 tinv Globigerina spends the greater part, 

 if not the whole, of its life on the 



FORAilEMFER.E FROM THE SURFACE OF 



THE SEA. 



Note how closely they resemble the fossil forms found 



in chalk. 



surface of the sea, where it forms its 

 minute shell, which only measures be- 

 tween 7;Vth and sV^h of an inch in dia- 

 meter, out of the carbonate of lime which 

 the little creature extracts from the sea- 

 water, and from the organisms upon 

 which it feeds. This shell is composed 

 of several globe-shaped chambers, the 

 walls of which are pierced by numer- 

 ous minute holes, through which the 

 creature protrudes a network of delicate 

 protoplasmic threads, by means of which 

 it captures its food. 



When they die, the Globigerina; slowly 

 sink to the bottom of the sea in countless 

 numbers, where they accumulate and 

 form about 85 per cent, of the ooze. In 

 this way a constant rain of millions upon 

 millions of these shells is for ever falling 

 from the surface waters to the floor of 

 the Atlantic Ocean, where they are slowly 

 building up a chalk formation which is 

 identical in general character with the 

 chalk clrffs of England, and which in the 

 fulness of time will rise, or be thrust by 

 some great submarine upheaval, above 

 the surface of the sea to form, perhaps, a 

 new Albion or Atlantis. 



Such, in brief, is the story of the white 



38 



chalk cliffs of England. In the dim 

 geological past they were formed beneath 

 the surface of an ancient sea that covered 

 the Western half of the Old World from 

 Britain to the Hindoo Koosh. Gradu- 

 ally, through the j^assage of the centuries, 

 they have been raised above the sea and 

 have assumed the form and aj^pearance 

 with which we are so familiar. 



Solid and majestic as they look, Nature 

 is at work upon the cliffs with her keen 

 tools — the rain, the winds, the frost, and 

 the waves — slowly but surely smoothing 

 and wearing them away. Those jiortions 

 which fall into the sea are crushed into 

 the finest particles and carried away by 

 ocean currents to be absorbed by and 

 built up into the shells of the Forameni- 

 jcrce, the rest to sink slowly, along with 

 those minute shells of the Globigerinae, 

 to the floor of the ocean, to help in 

 the formation of the chalk cliffs of a 

 future land. Truly, as we examine those 

 towering, majestic chalk cliffs, and realise 

 how Nature is for e\'er at work upon them, 

 changing, though ever so gradually per- 



OOZE FROM THE BOTTOM OF THE NORTH 



ATLANTIC. 



It is composed almost entirely of Globigerina shells. 



haps, their shape, the beaut}' of Tenny- 

 son's lines, and their perfect description 

 of what is for ever taking place, is vividly 

 brought before us — 



"The hill.s are shadows, and they flow 



From form to form, and nothing stands; 

 They melt like mist, the .solid lands. 

 Like clouds they shape themselvrs and go." 



F. Martin Duncan. 



