382 71. AMENTIFER^. 



Estimate of provinces 6. Estiinate of counties 1 2. 



Latitude 55 — 58. Highland type of distribution. 



Arctic region. Inferarctic — Midarctic zones. 



Descends to 550 yards, in East Highlands. 



Ascends to 900 yards, in the same province. 



Range of mean annual temperature 41 — 38. 



Native. Ericetal. A scarce shrub, probably rendered 

 more scarce by the periodical bm-ning of the heaths and 

 moors, in order to produce better pasturage for sheep. 

 The locality in Northumberland, and perhaps those in Ber- 

 wick and Lanark, may be within the agrarian region. 

 Mr. Babington thhiks that we have two species under this 

 name in Scotland ; and it is reported that B. intermedia 

 has been found in Forfarshire. 



995. PopuLUS ALBA, Linn. /u. /^M/ j^. ^^y 



Area 12345*789*11* (13) 14 (15 16) * [18]. 



South limit in Cornwall, Dorset, Sussex, Kent. 



North limit in Northumberland, Edinburgh ? Lanark ? 



Estimate of provinces 12. Estimate of counties 40. 



Latitude 50 — 56. English type of distribution. 



Agrarian region. Inferagi'arian — Superagi'arian zones. 



Descends to the coast level, in the Peninsula. 



Ascends to 200 yards, more or less, in Tyne. 



Range of mean annual temperature 52 — 46. 



Native, Sylvestral, Septal. Uncertain whether this 

 tree ought to be deemed indigenous in Scotland. Maccul- 

 loch said that a few stunted plants of this species compose 

 all the trees in the island of Lewis, Outer Hebrides ; which 

 was certainly an error, since Balfour and Babington men- 

 tion the P. tremula as the only species of the genus seen 

 by them in the Hebrides. Dr. Balfour gives the name of 



