15 



CHAPTER III. 



TEREDINES IN LONDON CLAY. PRE-ADAMITE HISTORY. — THE 'WOOD-EA- 



TER.' ATTACKS ON THE GATES OF ARDROSSAN. PREVENTIVES. — GOING 



AGAINST THE GRAIN. 



TEREDINA. 



Connected with the history of our recent ship worm s^ is a 

 geological fact which will illustrate the mauner in which the 

 study of living nature throws light on the history of the 

 past. In the beds of clay on which our metropolis stands^ 

 there are found buried deep blocks of timber pierced through 

 by the Teredina, an extinct genus of borers, which must 

 have been an animal of similar nature ; and, as Sir Charles 

 Lyell observes, there must have been a period when this 

 wood, now many feet below the foundations of a large city, 

 floated on the water, and again we are carried back to the 

 time when the tree was living. With this block in our 

 hands, then, what a history of by-gone time can be traced ! 



