Chap. X. TREES. . 363 



leafing so much, earlier than the others. There is also an oak near Edin- 

 burgh, which retains its leaves to a very late period. These differences 

 have been attributed by some authors to the nature of the soil in which the 

 trees grow ; but Archbishop Whately grafted an early thorn on a late one, 

 and vice versa, and both grafts kept to their proper periods, which differed 

 by about a fortnight, as if they still grew on their own stocks. 158 There 

 is a Cornish variety of the elm which is almost an evergreen, and is so tender 

 that the shoots are often killed by the frost ; and the varieties of the 

 Turkish oak (Q. cerris) may be arranged as deciduous, sub-evergreen, and 

 evergreen. 159 



Scotch Fir (Pinus sylvestris).—! allude to this tree as it bears on the 

 question of the greater variability of our hedgerow trees compared with 

 those under strictly natural conditions. A well-informed writer 160 states that 

 the Scotch fir presents few varieties in its native Scotch forests ; but that it 

 " varies much in figure and foliage, and in the size, shape, and colour of its 

 •" cones, when several generations have been produced away from its native 

 " locality." There is little doubt that the highland and lowland varieties 

 differ in the value of their timber, and that they can be propagated truly by 

 seed ; thus justifying Loudon's remark, that " a variety is often of as much 

 importance as a species, and sometimes far more so." 161 I may mention one 

 lather important point in which this tree occasionally varies ; in the classi- 

 fication of the Conifers, sections are founded on whether two, three, or five 

 leaves are included in the same sheath; the Scotch fir has properly only 

 two leaves thus enclosed, but specimens have been observed with groups 

 of three leaves in a sheath. 162 Besides these differences in the semi- 

 cultivated Scotch fir, there are in several parts of Europe natural or geo- 

 graphical races, which have been ranked by some authors as distinct 

 species. 103 Loudon 164 considers P.pumilio, with its several sub- varieties, 

 as Mwjhus, nana, &c, which differ much when planted in different soils 

 and only come "tolerably true from seed," as alpine varieties of the 

 Scotch fir ; if this were proved to be the case, it would be an interesting- 

 fact as showing that dwarfing from long exposure to a severe climate is 

 to a certain extent inherited. 



The Hawthorn (Crataegus oxycantha) has varied much. Besides endless 

 slighter variations in the form of the leaves, and in the size, hardness, 

 fleshiness, and shape of the berries, London 163 enumerates twenty-nine 

 well-marked varieties. Besides those cultivated for their pretty flowers, 

 there are others with golden-yellow, black, and whitish berries; others 



158 Quoted from Koyal Irish Aca- 162 'Gardener's Chron.,' 1852, p. 693. 

 demy in 'Gardener's Chron.,' 1841, p. 163 See ' Beitrage zur Kenntiiiss Euro- 

 767. paischer Pinus-arten von Dr. Christ: 



159 Loudon's 'Arboretum et Fruti- Flora, 1864.' He shows that in the 

 cetum;' for Elm, see vol. iii. p. 1376; Ober-Engadin P. sijlvestris and rnontana 

 for Oak, p. 1846. are connected by intermediate links. 



i 60 ' Gardener's Chronicle,' 1849, p. 1M ' Arboretum et Fruticetum,' vol. 



822. iv. pp. 2159 and 2189. 



161 ' Arboretum et Fruticetum,' vol. 1G5 Ibid., vol. ii. p. 830; Loudon's 



iv. p. 2150. ' Gardener's Mag./ vol. vi. 1830, p. 714. 



