78 



The Beech, {Fagus Sylvestris :) 

 The Birch, {BeMa Alba :) 

 The Bird Cherry, {Pnmus Padm :) 

 The Wild Cherry, (P. avmm :) 

 The Sloe Tree, or Blackthorn, (P. spinosa ;) 

 nor on any of the cultivated cherry or plum trees. 



The Hornbeam, ( Carpt'mis Betulus :) 



The Elder, {Samhwus nigra :) 



The Holly, {Ilex Europcca : ) 



The Dogwood, ( Cornus Sanguineus :) 



The Box Tree, {Buxus semper-virens :) 



nor has the Mistletoe been observed on any of the following 

 trees naturalized here : — 

 The Lombardy Poplar, (Populus fastigiata :) 

 The Sweet Chesnut, ( Castanea vesca :) 

 The "Walnut, fJuglans regia) 

 The Laurel, ( Cerassus ColcMcum :) 



nor on any of the other many introduced varieties of trees, 

 and evergreens. 



"Why the Mistletoe shoxild attach itself to certain trees in 

 preference to others, is a mystery not yet fully solved. Common 

 observation always refers it to some peculiarity in the bark, and 

 seems, oddly enough, pretty equally divided in opinion as to 

 whether the Viscum prefers a smooth and hard bark, or one 

 that is rough and porous. De. Haelet from his observations, 

 was led to suppose, "that a difference in size, number, and ar- 

 rangement of the medullary rays might explain it, and serve to 

 determine, in any given case, the attachment of the Mistletoe ; " 

 and he, accordingly, guided by their minute anatomical structure, 

 has arranged a list of thirty trees in the supposed order of their 

 liability to become the site of the pai'asite. — On dividing the list 

 into three groups, the ten trees most predisposed to bear Mistle- 

 toe — and in the order in which they stand, — are stated to be : — 



