316 



portions become gradually thickened by the formation of woody layers upon their 

 surfaces. This increase in the lateral dimensions of the root takes place, pari 

 passl^, with that of the branch upon which it grows ; for every layer of wood 

 deposited on the branch, a corresponding one is deposited upon the Mistletoe ; 

 and the growth of the two plants proceeding thus uniformly, the concentric rings 

 of the stock pass uninterruptedly into those of the Mistletoe, and the woody layers 

 become co-incident. Whilst the roots thus undergo increase and ligniflcation 

 about their outer portions, their inner extremities which now lie deeply within the 

 hard wood constantly retain their original soft cellular condition ; they are in 

 fact to the viscum what the cellular rootlets of terrestrial plants are to them." 



II. — The Trees upon which the Mistletoe Grows in Herefordshire 



so far as I have been able to ascertain them by my own observation, and with 

 the kind assistance of several members of our Club, and others, are as follows ; 

 and I give the list, as closely as may be, in the order of the frequency of its occur- 

 rence on the trees at this time : — 



ist. — The Apple Tree, {Pyrus mdlus domestica) general throughout the 

 Countv. 



f 



\ 



On the English Poplars : — 



2nd. — The Abele Tree or White Poplar, (P. alba ;) not common. 

 3rd. — The Grey Poplar, {P. canescens ;) rare. 

 4th. — The Aspen, (P. tremida ;) occasionall}' ; and on the following 

 introduced varieties of Poplar. 



5th. — The Black Poplar, (P. nigra ;) the earliest introduced species; 

 very common. 



6th. — The Black Italian Poplar, (P. monolifera ;) introduced in 1772, 

 and has now for the last 30 years been substituted by nurserymen for the 

 Canadian Poplar ; very freely. 



7th. — The Canadian Poplar, (P. Canadensis) formerly much more 

 generally planted than at this time ; very common. 



8th. — The Ontario Poplar, (P. candicans) a balsam bearing Poplar, 

 introduced from North America in 1772, and now much distributed by 

 Nurserymen ; common. 



The Mistletoe grows more or less on all these varieties of Poplar. I bracket 

 them together as a class, for in the reports sent to me, no distinction has been 

 made between them, and when the leaves are off the trees it is very difficult to 

 do so. 



Oth.^ON THE Hawthorn, {CratcBgus Oxyacantha) not uncommon throughout 

 the County, where old trees are found. Round Haywood Forest ; Belmont ; 

 Breinton ; Dinedor ; Lyde ; The Weir, Hereford ; Holme Lacy ; Harewood 

 Park : Ledbury district : Ross district (Rev. W. H. Purchas) ; Leominster 



