170 THE PARKS AND aABDENS OF PARIS. [Chap. XL 



acres, entirely devoted to the raising of the commoner and more 

 useful kinds of trees for avenue and boulevard planting. On 

 entering, the first thing that strikes the visitor is, that the whole of 

 the surface of the ground is thrown into ridges nearly six feet 

 in width, on the apex of which the trees are planted. This 

 arrangement is adopted in consequence of the ground being 

 occasionally flooded by the river Marne, which is close by, to prevent 

 the trees being injured by the water freezing above the base of their 

 stems. The kinds mostly raised are the Western Plane, the Horse- 

 chestnut, the large-leaved Elm, Ailantus glandulosa, Planeras, 

 and Lombardy Poplars — the last, however, are not used for 

 avenue or street planting. Other kinds used on a smaller scale 

 than these — the Paulownia, for example, are grown at Longchamps. 

 These trees, the names of which are here mentioned in the order 

 of their importance, are all trained with straight stems, and sent 

 from hence to the boulevards for planting as far as possible of 

 equal size.. The rule is to send them out with a straight stem of 

 nearly ten feet long, and about eight inches in circumference. The 

 portion above the ten feet of clear stem is not of so much 

 consequence and may vary, but if the trees when taken up for 

 planting do not present the length of " clean " stem considered 

 necessary, the lower branches are cut away till it is attained. Of 

 course the trees are so pruned when young that straightness of 

 stem is obtained. To arrive at the size and fitness for street- 

 planting, the Plane requires about five years, the Horse-chestnut 

 ten, the Ailantus four, the Elm and Planera about five years each. 

 The Elm and Planera are the only trees that require support in 

 training them into the necessary form, for which purpose stakes 

 from fifteen to eighteen feet high are used. 



The nursery for shrubs is very pleasantly situated near the 

 racecourse of Longchamps in the Bois de Boulogne, and is some- 

 what more than twelve acres in extent. It is in excellent keeping, 

 and contains a good stock of both well-known and rarely-used 

 subjects. Eoses and all kinds of shrubs and hardy climbers are 

 grown here for the city-gardens, as well as nearly every kind of 

 low tree. 



The nursery for hardy flowers is situated in the Bois de 

 Vincennes, and consists of nearly twenty acres of sandy ground 

 just outside the fortifications, near the Porte Picpus and Lac 



