A STTRVKV OF THE I.OWEK TEES IVfATtSHES I09 



railway existed, it seems to have been more extensive, occupy- 

 ing a saucerlike hollow now partly covered by ballast. 

 Whether the bed is natural or not is doubtful, but if one is to 

 judge by the occurrence of the Salt'x thicket in the TroUius 

 Marsh, and the sporadic appearance of Salix vhninalis, 

 S. caprea and 6*. triandra elsewhere the chances are that it is 

 so. Even if artificial, since it occurs in a suitable habitat for 

 its dominant Salix viminalis, and further because it has 

 existed at least a hundred years*, it has attracted to itself 

 plants proper to the Salicetum of the marsh. It must, how- 

 ever, not be regarded as uniform throughout, as in the deepest 

 part of the depression, where a constant depth of water stands, 

 a local association in which Fhragmi'tis holds the premier 

 position is apparent. 



The vegetation does not depart greatly from the average of 

 the TroUius Marsh ; nevertheless, a few plants not seen there 

 are present in addition to the chief Salix. The most import- 

 ant of these is Geum rivale, of sparing occurrence in south- 

 east Durham now, and obviously rare enough a century 

 ago to warrant a recordf of its presence in this precise 

 station then. Another novelty is the Aspen {Fopi/lns 

 tre?/iula) which, despite Baker and Tate's cheerful remark|| that 

 it is frequent in woods and hedges, is exceptionally rare in 

 Durham ; at any rate, frequent botanising excursions through- 

 out the county have only shown its occurrence, and that 

 sparingly, at two other stations. Here also Populiis nigt-a 

 intrudes, probably, in view of its liking for railway sides, as a 

 "passenger" from some wooded area. Tanacetuni znilgare is 

 another item foreign to the Ti'ollins Marsh. 



Appended are the contents of the Osier bed : — 



Salix viminalis d Spiraea Ulmaria a 



Phragmitis vulgaris Id Geum rivale f 



Ranunculus Ficaria a Crataegus oxyacantha o 



R. repens a Rosa spp p 



* Vide Brewster's " History of Stockton," Appendix II., page 46, 1S29. 



t I.e., page 46. 



II Baker and Tate's " New Flora," page 247, 1868. 



