io4 



THE DARLEY YEW. 



The oldest and youngest trees, therefore, had increased five 

 inches in girth in the first seven years, and the other four inches ; 

 and, if the former continued to increase at the same rate, they 

 would reach the girth of 360 inches, or 30 feet, in 504 years ; and 

 the other in like manner would reach the girth of 30 feet in 630 

 years. But it ought to be mentioned that this tree is much less 

 vigorous and luxuriant in appearance than the others. 



In the first ten years, the youngest tree had increased seven 

 inches in girth, and at the same rate it would reach the girth of 

 360 inches, or 30 feet, in 5i4f years ; and the two other trees had 

 gained six inches each in that time, or at the rate of a foot in 20 

 years, and 30 feet in 600 years. 



It will be observed that in the last period of three years No. 2 

 had increased more rapidly than previously, and No. 3 more 

 slowly ; but there is nothing unusual in such a change. A growing 

 tree every year makes an addition round its bole, which is com- 

 monly called a ring, and these rings vary occasionally in their 

 breadth ; sometimes the change is considerable, and sometimes 

 there has been a regular series of broad rings for some years, and 

 then a succession of narrow rings, followed by a series of broad 

 rings again of various sizes. [The head of a crutch of Baltic fir, 

 which was exhibited, was a very remarkable instance of all these 

 things. Although none of the rings in it were broad, there were 

 many variations in size. In one part there was a continuous 

 series of rings so small as to be hardly visible, and altogether 

 about an inch wide, and broader rings suddenly on both sides. 

 It is often difficult, if not impossible, to discover the cause of such 

 variations ; but in this case the fir may have grown in a forest, and 

 been all but smothered by surrounding trees during the time of 

 the formation of the small rings, and these trees may have been 



