DECORATIVE TREATMENT OF THE PIXETUM. 281 



Pruning of Pines. — The fir tribe, ^hen gro^vn in close 

 plantations, require little or no pruning. In the Pine- 

 tum, a moderate application of the knife is beneficial to 

 many of the species. Owing to diSerences of climate, 

 or variation in the pressm'e of the atmosphere from dif- 

 ferences of altitnde, some of the sorts, Tvhich are taU 

 trees in their own countries, are apt to grow bnshy with 

 us; or, from accidental circumstances, some of the 

 higher lateral branches may show a disposition to com- 

 pete "»vith the leading shoot. In aU these cases the thin- 

 ning out of the branches, especially the small ones, and 

 the foreshortening of those which are acquiring an ex- 

 cessive or iiTegular luxuiiance, will be foimd useftd, par- 

 ticularly in the Cedrus, Picea, and Abies groups. The 

 object kept in ^iew should be to dii'cct the flow of sap 

 to the head and shoulders of the ti'ee ; but it ought to 

 be regarded as a first principle that, by pruning, the na- 

 tural form of growth is to be promoted, and not con- 

 strained into anything artificial. IMr. ^I^Xab, of the 

 Edinbui'gh Botanic Garden, who has inherited and ac- 

 quired much experimental knowledge in this department 

 of arboriculture, has found that the prmiing of trees 

 in the Pinetimi is most successfidly performed in Jidy. 

 This result indicates that the proper time for this work 

 is when, the season^ s growth being far advanced, and 

 the flow of sap abated, there is little danger of an ex- 

 cessive exudation of resinous matter from the woimds. 

 We may add, that it is generally inexpedient to take off 

 lai'ge limbs from this class of trees. 



Decorative treatment of the Pinetinn. — The Pinetum 

 when planted separately, as it is desirable it should be, 

 is best aiTanged in groups with irregidar lawns passing 

 between them ; — the lai'ger trees occup^-ing the leading 



