Marcu 10, 1904] 
NATURE 
435 
The concluding section treats of solid geometry, after 
Euclid xi., and of the mensuration of simple solids. 
Particular care has been taken in regard to the 
figures; they are drawn in oblique parallel or metric 
projection, are lightly shaded, and are very effective 
indeed. A few problems on the setting out of such 
figures to scale, and of the measuring of dimensions 
from them, 
tive. Also in this section we should like to have seen 
some account of the graphic representation and 
measurement of position in space by means of ortho- 
gonal projections. In the geometry of the prism, 
pyramid, wedge, cylinder, cone and sphere, geo- 
metrical, algebraical and trigonometrical methods are 
very happily and naturally combined, resulting in a 
fuller treatment than is usually met with in similar 
text-books ; many well selected numerical examples are 
worked out. The prismoidal formula is explained and 
applied to specific cases. Altogether the author is to 
be congratulated on the production and completion of 
a very excellent text-book of elementary geometry on 
modern lines. 
In the ‘‘ Rudiments of Geometry ’’ the author gives 
a course which she claims to have introduced success- 
fully at the Municipal Technical School, Gravesend. 
It is based on experimental work, and is carried 
on along with practical geometry. Specific drawing 
exercises are set, and the pupils are required in each 
case to write out in their own words an account of 
what they have done, and of any inferences or dis- 
coveries they may have made. Formal proofs then 
follow, and are intended to be based on the collective 
suggestions of the class; these in turn are reproduced 
on paper by each boy or girl independently. There 
are two appendices containing between four and five 
hundred exercises in geometry. 
school of art course is too prominent. It seems to us 
that the scheme of the book is unduly extended, and 
that the work must suffer from lack of freshness and 
variety before the pupils have proceeded very far. 
There is little that we can commend in the geometry 
of Mr. Boulton. The author attempts to cover too 
much ground in the comparatively small space avail- 
able, so that nothing is very satisfactorily 
plished. 
accom- 
OUR BOOK SHELF. 
Ansichten und Gesprdache iiber die individuelle und 
specifische Gestaltung in der Natur. By Franz 
KraSan. Pp. vii+280. (Leipzig: Engelmann, 
1903.) Price 6s. net. 
Tuts quaint but very serious book is an expression of 
the author’s attempts to reach some clearness in re- 
gard to the conceptions of species, variety, breed, &c., 
which he has had to deal with in the course of his 
betanical studies. He discusses the profoundest 
questions of biology :—How far is organic form a func- 
tion of organic substance ? What is the nature of re- 
action to surroundings? Can one distinguish between 
th: original and the accessory characters of in- 
dividuals? What is the real meaning of metamor- 
phosis and substitution of organs? What is the 
evolutionary import of variation and mutation and 
NO. 1793, VOL. 69] 
would have been interesting and instruc- | 
In these the old | 
medification? How are we to define species, variety, 
and breed? What is the scope of hybridisation and 
in-breeding, of isolation and selection? In short, 
Iranz KraSan traverses the whole field of evolution- 
theory. And yet the result, to our mind at least, is 
deplorable—nothing short of a pathetic waste of careful 
and assiduous thinking, for he has cast his book in 
the form of dialogues between Arthur, Erwin, Fritz, 
Julius, Raimund, Walther, and possibly some others 
whose acquaintance we have not been able to make! 
They are most honourable gentlemen, with a facility 
of discourse and a knowledge of biology that make 
one blush; they bid one another a most courteous 
‘““Auf Wiedersehen ’’ after discussing ‘*‘ System und 
Phylogenie,’’ or the Hieraciums of Central Europe; 
they reappear cheerful and cocksure, lilke Job’s 
friends, to reiterate their various convictions, while 
the reader undevoutly wishes that they would all die 
off and leave Franz KraSan to tell us in plain German 
what he really means. 
We are told that the ‘‘ sachkundige Leser,’’ which 
we had mistakenly assumed to mean ourselves, should 
have no difficulty in appreciating the incognitos of 
Arthur, Erwin, Fritz, and Company, but there are 
puzzles enough in nature without making more in 
biological literature, and we “‘ give it up.’’ Not, how- 
ever, without saying that the “author has the results 
of much careful work and thought to communicate, 
the pity being simply that he has hidden his light 
under the bushel of a method of presentation which 
is anachronistic, repellant and absurd. We hope that 
he will feel himself impelled to part company with 
| Arthur, Erwin, Fritz, &c., and tell us in a short essay 
what he really thinks about individual and_ specific 
characters as these occur in nature. JAG: 
| Vegetationsbilder. By Dr. G. Karsten and Dr. H. 
Schenck. Plates 48. (Jena: Gustav Fischer, 1903.) 
| Botanists have been distinctly tardy in taking advan- 
tage of the facilities offered for introducing photo- 
graphic illustration into descriptive books. Some 
American elementary text-books contain very excellent 
| flower studies and ecological scenes, but practically the 
only standard work in which full advantage has been 
taken of photographic reproduction Schimper’s 
““ Pflanzengeographie,’’ in which the epoch-making 
physiological treatise is embellished with magnificent 
illustrations. 
It may be assumed that the success of Schimper’s 
book prompted the publication of this work, in which 
the illustrations form the main feature, and the text 
is added by way of explanation and comment. The 
worlk has been issued in eight parts, each of which 
may be purchased separately, and each part contains 
six plates illustrative of a particular region or repre- 
senting plants associated by common characters. 
Three parts deal with tropical lands in which moisture- 
loving plants abound, and these contain illustrations 
of rain-forests in Mexico, Java, and Brazil. The 
superabundance of vegetation does not lend itself well 
to photography, but the extyaordinary development of 
climbing aroids and epiphytes is well shown. Another 
conspicuous feature of these regions is the prevalence 
of large-leaved plants—species of Heliconia, Calathea, 
| Begonia, and many belonging to the order Mela- 
stomaceee—which constitute the ground vegetation. 
Owing to the more obvious characteristics and the 
reduced number of plants growing in dry or exposed 
situations, the photographs of South African scenes, 
of the seashore vegetation of Brazil, and of Mexican 
types are the most successful. Of the general 
character sketches, interest attaches to that showing 
the growth of Ipomoea pes-caprae, but quite the most 
| striking is the illustration of the spread of the sedge 
is 
