Effects of Fracture of Trunk 77 



trees of this interesting variety are, according to 

 Loudon, at Comber in the County Down. They 

 are supposed to have been planted before 1780. 

 In 1838 one of these had attained the height of 

 2 1 feet. The circumference of the trunk at i foot 

 from the ground was 4 feet 5 inches. This gives 

 an increase of i4'i inches in fifty-eight years, which 

 is largely in excess of that of the common form, and 

 is evidently due to the peculiar form of arrested 

 growth by which the full expansion of the tree is 

 curtailed and the trunk thickened as in a pollarded 

 tree. 



A still more striking instance of the influence 

 which arrested upward growth has in causing 

 thickening of the trunk is to be seen in the case 

 of two trees of this variety mentioned by Loudon 

 as existing at Nether Place, Ayrshire. These must 

 have been about the same age as the preceding, i.e. 

 planted about 1780. They both had their tops cut 

 away, and as a result had put out fifty-six and 

 sixty-six branches respectively, having a circum- 

 ference varying from 6 inches to 2 feet. The 

 trunks girthed 9 feet and 8 feet, or nearly three 

 times the average rate of increase of well-grown 

 common yews. The age of these by De Candolle's 

 reckoning would appear as 432 and 384, instead of 

 1 10 years. 



Rings of Wood. — It is not uncommon to find a 

 dead central trunk enclosed in old yews. Round 



