Reviews—Laterit an West-Australien. 383 
type (a) being in and near deep-seated Tertiary granites, type (6) 
associated with intrusive porphyries, and (c) with extrusive lava- 
flows. A notable feature in type (6) is the abundance of stannite, 
which by oxidation has given rise to large deposits of wood-tin. 
Bismuth minerals are also abundant, but the author does not mention 
wolfram, which has of late been largely mined in this area. A brief 
reference is made to the occurrence of argyrodite and other 
germanium minerals. The origin of the ores by differentiation of 
igneous magmas is discussed, and the unusual association of tin and 
silver is attributed to incomplete differentiation before eruption. 
The author considers that the ore-deposits of this area offer a 
favourable field for future development, though mining is hindered. 
by the great height of the country and the consequent severity of the 
climate. 
Vagal, Jaye 
LaTERIT IN WEST-AUSTRALIEN. By J. WALTHER. Zeits. d. Deuts. 
Geol. Ges. Vol. Ixvii, 1915, pp. 113-32, with 2 plates and 
1 text-figure. 
A CAREFUL examination of the laterite region of West Australia 
in 1915 and a comparison of it with many other regions have 
led the author to some general conclusions. In this paper he 
expresses his definite opinion that laterization is not a phenomenon 
characteristic of the present climate of moist tropical regions, as 
stated or implied by many writers. Professor Walther considers 
that laterization went on during a past climatic phase, when there 
was a very well-marked alternation of annual extremes of drought and 
rainfall. This he supposes to have occurred in the “ diluvial period ”’, 
whatever that may mean. As a matter of fact, this conclusion, as 
to the necessity for strongly accentuated wet and dry seasons for 
laterization, was reached many years ago by Indian geologists. 
This paper gives a graphic account of the peculiar topography and 
dry “lakes” of the more arid parts of Western Australia, and 
should be of service to all those interested in the subject. 
A GEoLogicaL Excursion HANDBOOK FOR THE BRISTOL DISTRICT. 
By S. H. Reynoxps, Sc.D., F.G.S., Second edition. pp. 224, 
with 50 figures. Bristol: J. W. Arrowsmith, Ltd. Price 
5s. net. 
V K observe with pleasure that it has become necessary to issue 
a second edition of this admirable handbook, first published 
in 1912. In view of much recent work on the geology of the Bristol 
district, a large number of small additions to and corrections of the 
text have been made, and five new illustrations are included. It is 
impossible to exaggerate the usefulness of books of this kind, written 
by competent authorities, and in this case the name of the author 
is a sufficient guarantee of adequate treatment. The Bristol district 
