(151) 
ing sorts. The Chinese juniper, and its striking form, of col- 
umnar habit, known as variety pyramidalis, are each present 
in a number of specimens. There are still other varieties of 
the Chinese juniper represented here. 
At the westerly end of this same area is the arbor vitae 
(Thuja). The species of this genus produce a durable wood, 
which is of especial value where there is contact with the 
soil. The Japanese arbor-vitae is represented by a single 
specimen. The common arbor-vitae, or white cedar, from 
northeastern North America, is fully represented, not only 
by the typical form, but by many horticultural varieties, some 
of them very decorative. The wood of this tree is valued 
for fence posts, railway ties, etc., and from its young branches 
fluid extracts and tinctures are made which are used in medi- 
cine. The Chinese arbor vitae, from China and Japan, has 
a number of specimens representing it and some of its horti- 
cultural forms. 
The maiden-hair tree family is represented by a single 
species, the maiden-hair tree, several specimens of which 
may be found on the southern portion of the westerly ridge 
of the herbaceous grounds. This interesting tree, with its 
fan-shaped leaves, is a remarkable relic of a type of vege 
tation which was common and widely distributed in tertiary 
geological time, but is now restricted to eastern temperate 
Asia in this one species, Gznkgo biloba. 
4. The Herbaceous Grounds 
The collection of hardy herbaceous plants is situated in a 
valley southeast of the public conservatories, and between 
the main driveway and the western border of the woods fring- 
ing the hemlock grove. This valley is about 500 meters 
long and averages about 100 meters wide. A small stream 
runs through the valley from north to south and is here and 
there broadened out into pools. The collections are arranged 
in two series: (2) The systematic plantation; (4) the morpho- 
logical garden; a third series (c) to illustrate economic plants, 
