THE TROPICAL 
AGRICULTURIST. [January 2, 1882. 
wells are called basins of disturbance, geologically, such 
as the noted ones of Paris and London ; and the other, 
basins of original deposition. Of the latter, we have 
several in Ceylon. In such cases, we see only the 
topmost beds and have no idea of what lies below 
except by trial. 
Such an inclined plane of deposition has recently 
been proved to exist, by the sinking of the cylinders, 
in the construction of the railway bridge not far from 
the Colombo and Kandy linp, and still later by the 
cylinders put down for the n»w Kelani bridge. That 
there is an actual dip, and that it is continuous be- 
tween the two there is not the slightest doubt, and 
from analogy and other borings and wells, there is 
reason to believe that such a basin of original depo- 
sition extends to a considerable distance on our western 
shore. 
It is very remarkable that nearly all our good wells 
in Colombo are close to the sea, eg., the large one in 
Kollupitiya in front of Stenart Place. One would 
naturally expect these waters to be distinctly brackish, 
but it is not so. We have no doubt one of the con- 
ditions of an artesian supply is the prevailing store 
of deposition, and if such be the case, might we not 
have been better served and at much less cost than 
by bringing our water-supply for Colombo so many 
miles? 
Other papers follow on Oligoclase granite and on 
Palaeontology. Mr. Bose gives a very able reply to 
Mr. Lydekker's criticism on " undescribed fossil carni- 
vora by P. N. Bose, B. Sc. London," which appeared 
a former Record. Mi. Bose is the first native gentle- 
man in India who has passed on to the Survey Staff. 
He gained high honors at the University, and promises 
o do good and useful work. 
"ARBORICULTURE."* 
A REVIEW, 
Mr. John Grigor, a well-known Scottish Forester 
and writer, has just published a work on Arboriculture 
dealing in a most exhaustive manner with the raising 
and managing of forest trees in Great Britain. Much 
that he has written cannot fail to be of considerable 
interest to planters in the tropics, cultivating, as they 
chiefly do, trees and shrubs of ligneous growth. In his 
chapter on acclimation, the author gives many remark- 
able instances of the effect of climate on the foliage 
and habit of trees, which render what has been found 
to occur in this respect in the case of the cinchonas 
all the more interesting and noteworthy. To quote 
briefly : — 
There is no tribe of plants with which I am acquainted 
that is eo susceptible of climatic influence as the 
ConiferEe. In the celebrated native pine forests in the 
Highlands of Morayshire any variety among the trees 
can hardly bo distinguished. But I have taken seeds 
from these, and after raising them, have planted them 
on the warm sands only a little above the level of 
the sea, where a variety foliage and habit became 
perceptible ; when these had yielded cones, and another 
* "Arboriculture, or a Practical Treatise on Baising and 
Managing Forest Trees and on the Profitable Exten- 
sion of the Woods and Forests of Great Britain. By 
John Grigor, the Nurseries, Forres, N. b., author of the 
Highland and Agricultural Society's prize essays 'on 
raising forest plants,' ' on forest planting, and on 
trees adapted to various soils and situations,' _' on 
raising and managing hedges,' 'on forest pruning, B 
•on the native pine forests of .'cotland,' 'on planting 
within the influence of the sea,' 'on the deodar,' 
'on tbe varieties of the larch cultivated in great 
Britain,' ' on the larch plantations of Scotland,' and 
on various other subjects connected with arboricult- 
ure.— Second Edition." 
generation of plants had been reared near the sea 
level, I have found many of them so far removed 
from the ordinary type, that some individual plants 
could scarcely be recognized as belonging to the species. 
This tree i9 found to accommodate itself to circum- 
stances, producing long or short yearly growths in 
proportion to the ripening influence of the climate 
which it inhab ts. A few generations of the tree 
existing in a high temperature would no doubt render 
its progeny nearly as tender as our greenhouse plants. 
The necessity for procuring seeds from acclimatized 
trees is forcibly shewn, and the worthlessness of the 
plants of Pinus syhestris or Scotch fir, grown from 
Continental seed, when planted in the north of Scotland, 
is instanced. Mr. Grigor's remarks on the necessity 
for seclecting nursery plante, a matter in which it is 
to be feared we are not sufficiently careful in Ceylon, 
are well worth quoting : — 
It is but reasonable to suppose that with the view 
of laying down a crop destined to stand for genera- 
tions — it may be for upwards of a century — every 
precaution would be taken to secure its vigour and " 
success, by selecting plants of the most approved 
varieties of the species ; in many instances, however, 
this is not done. Indifference, in this respect, with 
the trade, or with plant merchants, who pass the 
commodity from hand to hand in course of a few 
weeks, is not so surprising ; but with those who are 
to own the plants in their final destination, the eelec- 
tion is surely worthy of the exercise of thoughtfulness 
and care. Seldom, however, is this care taken, seldom j 
is the same vigilance exercised here, which the agri- 
culturist displays in laying down a crop destined to ] 
last only a few months. In arboriculture the result 
stands faraway in the future, whereas with the farmer 
it is close at hand — the character and quality of his 
crops are readily ascertained, and the difference between j 
good and bad is realized in a few months in a tangible 
form. In the formation of plantations, great or small, 
the work is generally proceeded with as if every tree or 
plant of its name were equally good, without regard 
to variety, pedigree, or climatic influence. 
On moorland, "notch planting" that is, the mere 
insertion of the plant into a notch made with a spade, 
appears the most successful method, 3,000 and more 
plants per acre being put out at a total cost of 10s 
in snme cases. Pit planting and trenching appear to 
be the most usual methods, but the low cost of form- 
ing a plantation by whatever method is certainly 
striking. Mr. Grigor's remarks on the necessity for 
thinning plantations are noteworthy : — 
Considerable loss is frequently sustained by produc- 
ing through confinement tall trunks without a propor- 
tionate diameter ; and unless the soil is very congenial, 
and the trees of great vigour, they are often slow to 
become stout or shapely when ample space has at 
last been afforded to them. In plantations formed j 
with plants at a distance of four feet, the thinning 
should commence when the plants attain to the height j 
of from twelve to fifteen feet, by removing the more . 
worthless kinds, which press too closely on the others, j 
and fully half the number of plants inserted per acre ' 
should be removed by the time that the most valuable 
portion is twenty feet high. When they attain the ■ 
height of thirty feet, they should stand on an average V 
fully seven feet asunder, or about 800 per acre. At I 
the height of forty feet, which is generally that num- 1 
ber of years' growth,* the trunks are formed to a con- 
* While in Southern India and Ceylon Eucalyptus 
globulus shoots up at an average rate of ten feet per 
annum, attaining a height of 100 feet in 10 years, and 
150 feet in the 15th year.— Ed. 
