342 
TirE NATIONAL NURSERYMAN 
and Liillels struck them. There are many noble speci¬ 
mens of Oaks, IJiekorics, and other deciduous trees, na¬ 
tive to Pennsylvania, hut few evergreens worthy of note. 
Some portions of the hattletield have been planted evi¬ 
dently to preserve the original conditions, hut a wrong 
selection of trees have been used. This is especially 
evident at Zeigler’s Grove, It was Joseph Meehan, the 
well known nurseryman, and horticultural writer, and 
veteran of the war, ith whom I had the pleasure of 
visiting Gettysbury, who first called attention to the 
planting of foreign trees at this point. 
There is something incongruous in the selection of 
trees used to replant this grove—Paulownia Imperialis, 
from China, Japanese Maples, Norway Maples, Cytisus 
Laburnum, English Ash, Carolina Poplars, and such like. 
They are all so different from the splendid native trees, 
and out of harmony with the surroundings so intensely 
American. 
The National Cemetery, with its noble monuments, and 
pathetic markers to the “Unknown dead,” is a part of the 
battlefield, but is an enclosure, well laid out, and beauti¬ 
fully kept. In it are some rather unusual specimens, 
although not indigenous to the locality, are quite appro¬ 
priate. The Norway Spruce are particularly fine for 
their age, and furnished to the ground; which is unusual 
lor trees of their proportion. 
Good specimens of Taxus Hibernica, Tsiiga Canaden¬ 
sis, Abies orientate, lietinispora squarrosa, Picea Nord- 
manniana, Taxus baccata, quite a variety of Thuyas, 
Magnotias, Japanese Maples, and even Taxodium dis- 
tichum, and Ilex Opaca are all worthy of note and evi¬ 
dently planted over 30 years ago. 
The superintendent told me the trees were not watered 
or fed, yet all looked remarkably vigorous and healthy 
and worthy embellishers of that sacred spot. 
PLANT INDUSTRY’S OFFICE OF ECONOMIC AND 
SYSTEMATIC BOTANY. 
The ofTice of the Bureau of Plant Industrv that does 
c/ 
systematic collecting of plants and plant products ol* 
economic value is called the Office of Economic and Sys¬ 
tematic Botany. Its collection contains samples of the 
j)rincipal economic ])lants of the world. 
The collection of this office are being constantly in¬ 
creased by additions from investigators of drug plants, 
l)oisonous ])lants, perfume plants, forage plants, orna¬ 
mental i)lants, economic trees and shrubs, and cultivated 
fruits, nuts and vegetables, to all of whom the collection 
is accessible. 
One of the tasks of this office, undertaken for the nur¬ 
sery trade, is the preparation of complete lists of orna¬ 
mental trees and shrubs now offered for sale in this 
(*ountry, with reference to the catalogues where descrip¬ 
tions of them may be found. By this means uniformity 
is secured in applying names to them. If these plants 
are already known under established names in the trade, 
it will not be possible to exploit them as novelties under 
new names. 
It is also the province of this office to name plants sent 
in for identification, such as plants injurious to cattle or 
sheep; noxious weeds; plants discovered to be especially 
ada})ted in certain localities for forage or for binding 
the sand on shifting dunes or along irrigating ditches, or 
for hedges. jOtber plants sent in may be suggested as 
sources for rubber or fiber or as remedies for certain di¬ 
seases. Once tbe botanical identity of the plant in ques¬ 
tion is established, and onlv after this has been done, can 
inquiries regarding the i)lant be definitely answered. 
In introducing new economic plants from abroad, cer¬ 
tain ones are found to be more suitable than others. It 
is the duty of this office to study the various introduced 
plants botanically, so that information may be recorded 
as to those found to be most desirable. 
One of the most important problems which this office 
is studying is the adaptation and development of crop 
plants suited to vast tracts of what is known as “acid 
land,” unsuited to the cultivation of the ordinary crops. 
The ofiice’s investigations have shown that certain plants, 
especially those of the heather and blueberry family, 
thrive only in such soils. Methods have been devised 
to propagate these plants by cuttings and by processes of 
breeding and selection, so that superior varieties have 
been produced. As a result, blueberry culture bids fair 
to become an important industry in localities where great 
areas of land have been hitherto considered unfit for cul¬ 
tivation. — 
PLANT FOOD. 
The fertility of a soil depends on a great number of 
circumstances, among which “plant food” plays a prom¬ 
inent part. We are getting more familiar as time goes 
on with the nature of this vaguely described article, 
which may be regarded as the very life blood of the 
plant. It is not enough to imagine so much salts of 
potash, nitrogen, or phosphates, and to assume that it 
will all be ultimately used by the plant. The condition 
of the plant food is now known to be very closely asso¬ 
ciated with the use the plant can make of it, and many, 
attempts have been made to get at the processes by 
which this is brought about. 
It must not be supposed that the mineral matter in the 
soil can be taken up unchanged. The “soil water,” as 
it is called, or, again, the acid excreted by the healthy 
knots plays a very important part in preparing minute 
quantities of food for the plant’s consumption, and it is 
still a matter of speculation how far carbonic acid, 
which the roots excrete, assists in the process, or 
whether this is the process at all, except, perhaps, in 
seedlings. 
A test of fertility, then, is found to consist in estimat¬ 
ing how' much plant food is extracted from a soil by 
treating it with some solvent closely akin to that made 
use of by the plant. Acetic, carbonic, and other dilute 
acids have all been used for this purpose, but the most 
favored is a very weak citric acid, because it is supposed 
to more nearly approximate to natural conditions than 
any other. It is for this reason that manures which are 
“citric soluble” are valuable as ])lant food, for the test 
is now applied as a guarantee of efficiency.— Journal of 
Horticulture. 
