42 Yew-Trees of Great Britain and Ireland 



growth as a single trunk, and in the majority of 

 instances decay or fracture has taken place, and 

 coincidently with either of them a series of remark- 

 able changes in rejuvenescence. 



Whenever the leading shoot or main stems of 

 a yew are broken, all the wood of that portion of 

 the trunk with which they are connected dies. 

 The bark coverings of the tree do not die, but at 

 once put forth a vast number of young shoots. If 

 these are deprived of light and air by overshadow- 

 ing branches, they die back and a fresh crop ensues. 

 This also happens if the shoots are eaten by cattle. 

 The swollen bases of these young shoots are covered 

 by the spread of the bark, giving rise to bosses 

 or a thickening which may extend in part or wholly 

 round the trunk. If the top of the tree is com- 

 pletely destroyed, the young spray grows thickly 

 all round the remaining portion of the trunk. The 

 shoots attain a considerable growth, and become 

 welded together, and in this way there arises a 

 rapid increase in the tree's girth. The smaller 

 shoots thus enveloped by the spread of the bark 

 produce a vast number of rings, which are eventu- 

 ally concentric, and in a measure resemble annual 

 rings, which they are not, as several or even many 

 of them may be produced in a single year. This 

 explains how in ' a yew that was dug up in a bog 

 in Queen's County, and which was proved (}) to 

 have been 545 years of age, it had grown so slowly 



