154 THE WONDER OF LIFE 



Hemisphere, but was brought near to extinction by the 

 severe conditions of the Great Ice Age. In size, majesty, 

 vigour, recuperative power, age and antiquity these 

 ' Big Trees ' command our admiration. They have the 

 distinction of having had a longer life than any other 

 living creatures — they make centenarians and the like 

 appear youngsters. 



The late Prof. W. R. Dudley recorded some precise data 

 on a subject which tempts to exaggeration. ' Of the vari- 

 ous trunks of Sequoia gigantea examined ranging from 900 

 years upward, the oldest possessed 2,425 rings, or had begun 

 its existence 525 years before the Christian era '. A tree 

 near a perennial stream was over 80 feet in circumference, 

 ten feet from the ground, but was only 1,510 years old; 

 another growing on a hillside not near a stream, had sufiered 

 from fire and from privations (fifty rings of scarce years 

 not covering an inch), and it was only 39 feet in circum- 

 ference, ten feet from the groimd, but it had attained the 

 age of 2,171 years and a height approaching 300 feet. 



Professor Dudley showed the extraordinary vitality of the 

 Big Tree by tracing out the way in which many of them had 

 been able to ' heal ' or cover over great wounds made by 

 fire. What a tree does is not to revitahze what has been 

 killed — that is impossible — ^but to extend or fold its Uving 

 tissue over the wound. ' There is no organic union 

 between the new wood of the folds and the wood of the 

 charred surface underneath them, no heahng at this point 

 of contact, in the ordinary sense of the word ; but 

 there is effectual covering, or healing in the rarer sense, 

 according to the tree trunk's way.' The process may take 

 scores of years. 



The tree already referred to which began its existence in 



