264 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY, 
we may infer that A. nobilis and A. lasiocarpa can subsist on 
a drier and poorer soil than can A. Nordmanniana and A. 
pectinata. 
It may be said that A. cephalonica and A. Pinsapo are not worth 
growing, and in many places they are not, but when growing on 
limestone or chalk they are highly ornamental. The same holds 
good with A. Albertiana, A. Menziesti, and A. excelsa, which are 
rarely seen in good form except on soil of a peaty description. 
Everyone interested in trees and shrubs knows that there are 
certain kinds which in a state of nature are only found growing in 
a peaty soil, mixed, it may be, more or less, with sand, and any 
attempt to cultivate them in other soils is productive of very 
unsatisfactory results. Who would ever think of planting the so- 
called American or peat plants, Cape Heaths, and the Epacris in, 
say, leaf soil, gravel, or loam; or Rhododendrons where lime is 
present in the soil? and these facts show us that there is something 
in the composition of certain soils only suitable for the roots of a 
certain class of plants. Another curious fact is this, that when 
growing on certain soils the timber of one species of tree is found 
to be far more durable than in others. Deep loamy soil and soft 
peat produce timber that is usually of a second-rate description, 
being deficient in firmness. 
I have long felt convinced that a great amount of good in point- 
ing out the trees that are best suited for various soils and formations, 
might be brought about by a careful study of the geological strata. 
As an illustration, we are here a distance of some seventy miles 
inland, and at varying altitudes from 300 feet to 700 feet above 
sea-level. Generally speaking, the soil consists of the different 
strata of the middle oolite; and to determine which trees thrive best 
upon it would be a most interesting study, as well as of the greatest 
value from a forestry point of view. As this stratum runs for a 
considerable distance and at greatly varying elevations, it would 
be valuable to learn what difference in the species of trees upon the 
various districts of it can be noted. The variation in certain trees, 
say, between the Kentish rag and chalk formation, or between the 
coral rag and the Oxford clay, lying next to it, is very striking, and 
well worthy of the attention of planters in these districts. There 
would be little difficulty in getting together a mass of informa- 
tion in this way, as reports from various districts throughout the 
country would be of almost universal interest in affording data to 
planters, 
