28 
steppes, woods, subalpine, alpine and high-alpine re- 
spectively, and these main subdivisions are broken up 
into smaller groups which exhibit some definite character 
by which they can be distinguished. A somewhat curious 
feature of the book rests in the inclusion of an account of 
the principal insect pests which are injurious to the 
cultivated plants. 
The Illyrian flora, as described by Dr. Giinther ritter 
Beck v. Mannagetta, is one which seems to be a promis- 
ing, if difficult, field of exploration, The plants of the 
maritime regions are, for the most part, an extension of 
the typical Mediterranean vegetation ; but in the higher 
levels, where the minimum temperature sinks below 14° C., 
it is succeeded by one of which the oaks form the charac- 
teristic feature. The swamp plants which occur in this 
zone consist, for the most part, of northern European 
forms, mixed with others of wide distribution. Still higher, 
the willows and pines form the distinctive land-marks, 
and these are finally succeeded by an alpine flora which 
varies in character in the different mountain groups. This 
is due largely to difference in geological character, and 
partly also to the isolation of the mountains themselves. 
The volume includes a short sketch of the Algz of the 
Adriatic coast, and ends with a discussion as to the re- 
lationships of the Illyrian flora with that of the surround- 
ing countries, especially with regard to the physical 
changes which have occurred since Tertiary times. 
The last, but by no means the least interesting, 
volume, by Dr. Graebner, deals with a more restricted 
formation, but this very circumstance affords an oppor- 
tunity for a more detailed treatment. The heath and 
moorland vegetation is one which fairly bristles with 
interesting problems, and the volume in question forms 
a useful contribution to the whole subject. Here and 
there, perhaps, the chemical aspects of the relation 
between plant and soil preponderate over the hardly less 
important biological ones. The author corrects a common 
error as to the relation between the heather and a lime- 
stone soil. He shows that the destruction of the heather, 
or;its non-appearance, is not due to the presence of the 
calcium salts directly, for he proves by experiment that 
in a sufficiently poor soil lime may be added in quantity 
without any injury to the plants in question. But a 
natural limestone soil is commonly also rich in other 
mineral constituents which are available for food manu- 
facture, and it is to the presence of these that its absence 
or extermination is due. Heather is, in fact, very sensi- 
tive to manure, which causes its disappearance from 
soils which may have been previously infested by it. 
It is, of course, quite impossible to do justice to the 
books under consideration within the limits of a short 
notice such as the present, but it is hoped that 
enough has been said to indicate their importance in 
helping to fill a serious gap in botanical literature. 
It may be fairly said, moreover, that each volume will 
be quite indispensable to anybody who may desire to 
make a close acquaintance with the scientific aspects of 
the floras of the regions thus severally dealt with. And, 
taken collectively, they render it possible to acquire a far 
more intelligent grasp of the facts, and therefore also of 
the problems, of plant distribution and ecology than has 
hitherto been practicable for most of us. 
NO. 1697, VOL. 66| 
NATURE 
[ May 8, 1902 
OUR BOOK SHELF. 
La Question de ? Eau potable devant les Munictpalités. 
By P. Guichard. Pp. 190. “ Encyclopédie Scientifique 
des Aide-Mémoire.” (Paris: Gauthier-Villars, n.d.) 
Price fr. 3; 
IN this work the author has brought together accounts of 
the water supplies of some twenty-six towns of France, 
giving details, as far as possible, of the source from 
which the water is derived in each case, of the treatment 
to which it is subjected before distribution and of its 
chemical and bacteriological character. These accounts 
are derived from analyses and reports furnished by the 
various analysts who have actually examined the sup- 
plies, and are of very varying degrees of completeness. 
The object which the author had in view in making his 
inquiries was to ascertain what method of purification, if 
any, was usually employed by the municipality to ensure 
the freedom of the water from the germs of disease. The 
answer to this question is that the municipalities select 
the best water at their disposal and deliver it to the con- 
sumers either without any treatment or after filtration 
through sand, Anderson’s iron process being used in a 
few cases. The author does not regard sand-filtration 
as by any means a satisfactory method of purification, in 
spite of the fact that experiments have shown that when 
properly carried out it is extremely efficacious, and that the 
comparative freedom from water-borne disease of towns 
like London, which make use of water known to be pol- 
luted, depends entirely on its use. No discussion of this 
or kindred points is given, and this somewhat detracts 
from the value of the book. After pointing out the 
numerous sources of contamination which may affect the 
water of towns both before collection and during dis- 
tribution, the author recommends all householders to 
protect themselves by purifying all water in their own 
houses by filtration or other means, and believes that 
only in this way can security be attained. A very proper 
and timely protest is made against the continued use of 
cemeteries for burying those who have died of infectious 
diseases, and also against the fashionable institution of 
cemeteries for pet animals, the infiltrations from all of 
which pass into the streams and rivers of the district, so 
that, as the author expresses it, “nous mangeons ou 
buvons de ’homme et duchien 4 une sauce non prévue 
dans les traités de gastronomie.” 
Plissements et Distocations de lécorce terrestre en Gréce 
By Ph. Negris. Pp. 210; 2maps. (Athens: C. Beck ; 
Paris: C. Béranger, 1901.) 
THE large questions raised by the author cannot be 
adequately discussed in a brief notice, so it must suffice 
to state his main facts and inferences, expressing doubts 
in passing. Since Jurassic times, successive earth-move~ 
ments have affected Greece and the adjacent parts of 
Turkey. The foldings produced are distinguished by 
local names. The earliest, or Olympic, which is pre- 
Cretaceous, runs from N.W. to S.E. along the eastern 
coast and a chain of islands as far as Karpalho. The 
Pentelic, closing that period, is at right-angles to it and 
acts more especially on the ‘2gean area, its western 
coasts and the Morea. The Achaic, which occurred 
during the Eocene, more or less affects the whole region 
and even Crete, running W.N.W. to E.S.E. The Pindic, 
closing the Eocene, trends in a N.N.W.-S.S.E. direction 
and can be traced in the Pindus mountains, the country 
to the west and the Morea. Last is the Tenarus folding, 
which began late in the Pliocene and affected the whole 
of the Greek kingdom, running from N. to S. All 
are generally associated with outbursts of igneous rock— 
peridotite (serpentine) in the earlier, trachyte in the later. 
There are also three important sets of faults, on which, 
however, we cannot dwell. The Tenarus folding pro- 
