THE SEQUOIA 



represent periods of interrupted growth, a tree carries its biog- 

 raphy within itself. During more favorable seasons, the circles 

 are wider, and the intensity of the winter intensifies the outlines 

 of the rings. 



"Mark Twain" upholds the reputation of the Big Tree for 

 longevity. The rings show that it was i;.|i years old when cut 



down in the fall of [891. Thus it must have begun its life in 

 a. i). 550. or only seventy-four years after the Fall of Rome. 



Practically all ^i medieval history, as well as modern, must be 



included in this period, while Natural Science or Biology may be 

 said to have developed during its old age. 



The small black cards which have been placed on the tree 



mark the successive centuries and give the growth of the tree 



during each hundred years. The uppermost row of while cards 



1619 



HARVEY 



Discovers circulation 

 of the blood 



indicates ]>< -litical events and disc< >verics which have had influence 

 on the progress of civilization since- the year 550. The remain- 

 show the progress in biology. The- group immediately above 

 black cards represents the change in thought in philosophical 



. while those below give a history of biology proper.* 

 When the tree was a mere sapling, Europe was overrun by 

 the Goths, Vandals and Pranks, and >f almost univ 



war prevailed. About twent} later Mahi 1 



ird is mounted 011 a pin which into the- ring 



tmple, in the accompai 



hat William 1 I 



into 



ird. In • 

 cases the pin ha tuck into I .-. th <>t the earlier 



! I 



