190 THE MICROSCOPE AND ITS LESSONS. 



wonder of wonders we call a leaf, and sometimes en- 

 close in a letter to one whom we love, and with it 

 write 



Only a leaf, yet it shall bear 



A wealth of love, of mintage true ; 

 Only a simple earnest prayer, 



That silently goes up for you ; 

 Yet you and I may never know 



What blessings from that prayer may flow." 



Do we say this because a leaf comes from a tree, 

 and the word " tree " comes to us from the same etymo- 

 logical root as "true"? Is a leaf the hieroglyphic of 

 truth ? 



Flint. Here is a very thinly cut section of a pebble 

 from the Norwich drift ; it is a mass of fossil remains of 

 animals and plants, the relics of the immeasurable past, 

 one of the many medals of the earliest days of the 

 creation of our world ; it is a striking illustration of the 

 truth of the words of Professor Owen, who once said that 

 every bit of coal had moved as sap in the vessels of a 

 plant, and each cliff and quarry of chalk and limestone 

 and marble once circulated in the vascular tissue of an 

 animal.* 



And here are various specimens of coprolites from dif- 

 ferent districts in England. The word divided signifies 

 " stone " and " dung" you would take the stone, of which 

 this section is a very thin slice, to have been a common 

 pebble such as you would have met with by the roadside. 

 Look at it, first with a low power ; then, as you always 

 should, increase it, and you will see that which, even 

 with your previous aid, was invisible. 



Let me explain to you, in a child's language, what 

 this section really is. 



* "Exeter Hall Lectures," 18C3-4. 



