48 
inspection of the districts by Mr. H. M. Jenkins, the re- 
cently elected Secretary of the Society ; who, fresh from his 
labours as Secretary to the Geological Society of London, 
has given, in addition to an insight into the methods em- 
ployed for improving the land, very clear and accurate 
sketches of the geology of each farm over which he has 
gone, illustrated in each case by a shaded map, expressing 
3. a] A\luvium (water-meadows ). 
= A\livium (wate ows ). 
Supsor. Mar, Scale—Two inches to a mile, 
the nature of the subsoil, and its bearing upon both the 
lithological nature of the soil, and its retentiveness of 
moisture—this latter point having a most important 
bearing upon its fertility, 
In illustration of the various conditions under which 
the surface soil is cultivated, we may refer our readers, 
first of all, to the recently issued number of the 
journal referred to, We there find, in an essay on 
Forest-farming, by Mr, Jenkins, that “the site of the 
ancient forest of Sherwood furnishes some of the best 
examples in England of successful farming, under circum- 
NATURE 
[Mov. 11, 1869 
stances of great natural difficulty. The subsoil consists 
of a sandy conglomerate, and is covered by a very light 
sandy loam of poor and hungry character. Little is 
yielded by it alone ; and the farmer looks upon it more 
as a vehicle whereby he can convey fertilising materials 
to his crops, than as a producer of their natural food.” 
Here we have a natural condition of virgin barrenness, 
forced into fertility by the most advanced appliances of 
agricultural science; and from this basis of natural poverty 
we may diverge, on the one side, into fields which, once 
naturally fertile, and possessing a rich store of accumu- 
lated wealth, have been impoverished, and even denuded, 
of their wealthy mantle of soil at any rate, by a very 
recent degradation ; and, on the other side, we may find 
examples where the wealth and fertility of a district are 
being continually increased by atmospheric causes. Mr. 
Jenkins gives us instructive examples of both sets of 
conditions, in one case both occurring on the same farm, 
viz. at Eastburn in the Yorkshire Wold: on one portion 
of the farm “the higher ground exhibits a soil gradually 
increasing in strength and depth as one ascends 
the hill;”,;while upon another portion of the farm, the 
thickness of the soil follows a rule precisely opposite 
to that just noticed: “instead of the depth and strength 
of soil increasing with the height, the opposite is now the 
case. The only essential physical difference in the two 
cases seems to furnish the explanation of this anomaly, 
namely, that we now have to deal with a we¢ valley of very 
slight slope, the soil on the sides of which consists of the 
mud (or warp) deposited by the stream in times gone by ; 
whereas, in the other case, the valleys are dry, and their 
slopes have been denuded of any alluvial soil which may 
formerly have covered them, by an agency which has also 
deepened the valleys and increased the pitch of their 
sloping sides.” All these practical descriptions, the result 
of actual survey, show clearly that the formation of soils is 
not always attributable to the same cause ; for we have in 
them clearly indicated three natural processes by which the 
surface-conditions haye been produced—yiz. (1) Soil 
formed from the subsoil immediately beneath ; (2) Soil 
formed by the denudation of soil and subsoil at higher 
levels ; and (3) Surface denuded of soil by degrading 
influences. The first two processes are formative, while 
the third is destructive; and thus in this, as in every 
other portion of nature’s economy, we at last learn that 
antagonism produces equilibrium. 
H, WOODWARD 
VEGETABLE PALEONTOLOGY 
Traité de Paléontologie Végétale, By Prof. Schimper. 
(Paris, 1869. London: Williams and Norgate.) 
[* asked to indicate the most suggestive discoveries in 
Geological Science that haye been made within the last 
ten years, we should unhesitatingly point to that of the 
Eozo6n,—to the unfathoming of the mysteries of the floor 
of the ocean,—and to the unearthing, in high Arctic 
regions, of forests of Dicotyledonous trees, not merely 
analogous in size, habit, and conditions of life, but 
specifically closely allied in structure to the forest 
trees of middle and southern Europe, Asia, and 
North America, The first of these discoveries carries 
