( 38 ) 
means of a critical study of the existing surface, and a slight 
modification of the position of the brook, we have been able 
to arrange the families in natural sequence, and to provide 
soil and exposure desirable for every species which will prob- 
ably exist in the open in our latitude. Abundant space for 
each group is assured, together with a large margin of safety. 
The brook which intersects these herbaceous grounds, while 
flowing most of the year and fed by springs, is sometimes dry 
in summer, and in order to effect a constant flow we have 
planned to turn into it the waste water from the First Horti- 
cultural House, which is to stand on a plateau immediately at 
the head of this valley. A further supply of water for this 
brook may be obtained from the overflow from the rockery. 
The area of the Herbaceous Grounds is about 8 acres. 
14. Rockery. 
In addition to the facilities for growing rock-loving plants 
afforded by the edges of the herbaceous grounds, a rockwork 
is planned for the cultivation of such, mainly for decorative 
effect, and in locating this we have taken advantage of a 
ledge of gneiss extending from a point about 200 feet east of 
the southern side of the First Horticultural House southerly to 
a point east of the herbaceous grounds. This affords both 
sunlight and shade in any proportion which proves desirable. 
In order to utilize the river water for the rockery and for the 
herbaceous grounds, we have planned to place a water engine 
on the Bronx below the gorge to pump water to a small tank 
situated on a ledge in the forest, which will supply plenty of 
pressure for distributing the water along the rockery and 
through the valley to the south and west. 
15. Bog Garden. 
There are large numbers of trees, shrubs and herbs whose 
natural habitat is in bogs, swamps or marshes, and while 
some of these will grow if cultivated on dry soil, they will all 
thrive better if grown in their natural habitat. With this con- 
