xxviii INTRODUCTION. 



LIMITS OF CULTIVATIOX.— The factors that modify these limits 

 are several, and no very definite general statement is possible as to the 

 line "where cultivation ceases. Broadly, it may be stated that cultivation 

 is nowhere carried beyond 800 to 900 feet, and that it ceases much below 

 that limit •where the rock is not well covered with drift, and the aspect 

 southern. The mineral characters of the rocks, and their structure, have 

 considerable influence on vegetation, but physical features may be said to 

 be stOl more potent in dictating to the husbandman. "Where the long 

 upward slopes permit soil to coUect there crops will repay labour, but 

 where the rise is rapid cultivation ceases at a much lower level. The 

 aspect, or position of the ground towards the sun, is of course of the utmost 

 importance. Mr. E. Glascott Symes, M.A., F.G.S., of the Geological 

 Survey, who knows the Coimty of Antrim so well, has kindly supplied a 

 note on this head as respects that county. Eev. H. W. Lett. M.A., 

 T.C.D., who has been much engaged in botanically exploring the Moume 

 Mountains, has also been good enough to furnish some particulars with 

 regard to County Down. The details communicated by Mr. Lett are in 

 substance as foUow : — 



About Newcastle, on the slopes of Slieve Donard and SUeve Comme- 

 dagh, the cereal line does not rise above 200 feet ; drift clay is absent, 

 and the groimd steep. On Tullybranagan the limit is still the same. 

 This is exposed to the north and east, and the mountains rise somewhat 

 abruptly behind, to the south and southwest. Proceeding south, at the 

 Bloody Bridge, also open to the east, the limit is 350, while further south, 

 at TuUp-ee, where there is an extensive moraine, the Line rises to 600 ; 

 but not far off, on the east slope of Spence's Moimtain, it drops to 200. 

 Along the sheltered banks of Spence's Eiver, and on the southern slopes 

 of SUeve Bignian, three miles inland, the cereal line is at 600 feet. 

 There are well sheltered farms on the road that passes through the 

 mountains, from Kilkeel to Hilltown, where the line gets up to 700 feet, 

 its highest point on the south of the range. About Rostrevor the indi- 

 genous woods blot out the cereal line, but at Kilbroney River it stands 

 at 700, while further north, at the favoured locality of Gruggandoo, it 

 ascends to 900. Along the glen west of Altatagart, through which 

 Shanky's River flows, the line is met with at 800 feet, but crops only 

 succeed in favourable seasons ; along the same northern slope, at Leitrim 

 River, it is 600, To the southeast of Hillto^vn the line descends to 500, 

 and between Hilltown and CastleweUan it is 650. Up the sides of the 

 Shimna River, to the north of Slievemeel Beg, the Limit is 700 feet ; 

 from this it descends to 400 where the Spinkwee enters the park. Slieve 

 Croob is a good deal isolated, and the slopes on all sides are gradual ; on 

 the east, north, and west sides cultivation reaches to 700, and on the 

 south to 800 feet. There does not seem to be much difference between 

 the granite and the schist districts, acclivity, drift clay, and shelter from 

 cold winds being the great modifying agents. 



Respecting the limits of culture in County Antrim Mr. Symes has not 

 paid special attention to the point. He is, nevertheless, a trained observer 



