71. AMENTIFER-E. 387 



gures, &c., which show the distribution of the triad, or 

 three units, treated as one single unit ; but the distribution 

 which it is my wish to ascertain and show eventually, is 

 that of each unit in the triad, apart from the other two units. 

 The data within my reach at present do not enable me 

 to accomplish this, because they do not enable me to sepa- 

 rate the errors from the true records of localities. 



^•f^^ 999. Salix pentandka, Linn. 



Area (1 2) .3 4 5 6 7 8 9 10 11 12 13 14 15 16 * (18.) 



South limit in Surrey, Pembroke. (Devon, Sussex.) <:^«- *»^»«<i<_ 



North limit in Moray .? Aberdeen, Argyle. (Hebrides.) 



Estimate of provinces 14. Estimate of counties 40. 



Latitude 51 — 58. Scottish type of distribution. 



Agrarian region. Inferagrarian — Superagrarian zones. 



Descends to the coast level, in Thames or Severn. 



Ascends to 100 or 200 yards, in Scotland. 



Range of mean annual temperature 49 — 46. 



Native. Sylvestral, &c. Considerable uncertainty at- 

 taches to the habitats of this shrub at each extremity of 

 Britain. It prevails chiefly in the Lowlands of Scotland 

 and Northern provinces of England. Balfour and Babing- 

 ton enumerate it among their species of the Outer He- 

 brides, but give for it only the very suspicious locality of 

 Roddal, in Harris, where, and where only, various other 

 doubtful trees and shrubs appear also to have been ob- 

 served. Though it is rare to the south-eastward of the 

 Trent and Severn, I am disposed to receive it as a native 

 of the Thames province. To the provinces of the Penin- 

 sula (Devon; Mr. Abraham) and Channel (Sussex; Mr. 

 Borrer) it may have been introduced. 



2 c 2 



