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NATURE 
31 
OUR BOOKSHELF. 
Das Pflanzenreich. Herausgegeben von A. Engler. 
Heft 48 (iv., 23C), Aracezw-Lasioidee. By A. 
Engler. Pp. 130. Price 6.60 marks. Heft 
49 (iv., 101, Nachtrage), Monimiaceze (Nach- 
trage). By J. Perkins. Pp. 67. Price 3.60 
marks. Heft 50 (iv., 50, ii. B. 21), Orchidacee- 
Monandre-Dendrobiine. Pars ii. Genera 
n. 278-279, and (iv., 50, ii. B. 23) Orchidacez- 
Monandree—Thelasine. Genera 280 and 28o0a. 
By Fr. Kranzlin. Pp. 182+46. Price 11.60 
marks. (Leipzig: W. Engelmann, 1911.) 
Tne subfamily Lasioidee includes Amorpho- 
phallus, Rhektophyllum, a West African climber, 
Montrichardia, an arborescent form, and many 
tuberous-stemmed platits such as Thomsonia 
nepalensis ; vegetative shoots or bulbils are nor- 
mally developed from such tubers, being produced 
in great profusion by Dracontium asperum. 
Entire sagittate leaves are not uncommon, but a 
much divided leaf with sagittate outline is more 
typical. The spadix is exceedingly variable in 
form; in the case of Amorphophallus rex it 
bears a peculiar appendage and a_ singular 
spathe. The various phylogenetic relationships of 
the various genera are discussed at length. Cyto- 
spermum is regarded as the most primitive on 
account of its perigoniate hermaphrodite flower, 
the presence of endosperm in the seed and its pan- 
tropic distribution; the genera Nephthylis and 
Montrichardia are placed at the other end of the 
scale by reason of their naked unisexual flowers 
and poral dehiscence of the anthers. 
The supplement to the early volume on the | 
Monimiacez contains the additions that have 
accumulated in ten years. A compliment is paid 
to a well-known benefactor by the establishment 
of a new genus Carnegiea, although the associa- 
tion with a type specimen from New Caledonia is 
not immediately obvious. Two new myrme- 
cophilous plants are noted in Steganthera insignis 
and S. torricelliensis. 
The fiftieth part is principally a monograph of 
the genus Eria, in which the author follows 
Lindley except in the separation of the subgenus 
Trichotosia; with these two, Porpax is closely 
associated, but Phreatia is removed from the 
Dendrobiine to a new combination with Thelasis. 
Primitive Animals. By Geoffrey Smith. 
156. (Cambridge: University Press, 
Price Is. net. 
In this book the author gives a concise account of 
the principal characters of a number of primitive 
animals, and of the arguments based upon their 
study. He first shows the great antiquity of the 
Pp. x+ 
IQII.) 
‘chief phyla by instancing the fact that in the 
oldest fossil-bearing rocks (Cambrian) there are 
representatives of certain families of Crustacea 
(Nebaliidee, Cypride) which exist at the present 
day. In considering the lowest forms of life, 
the author points out that animals depend ulti- 
mately for their food upon plants, and suggests 
that “the presence of chlorophyll was the neces- 
sary precursor of life,’ but concludes that the 
NO. 2211, VOL. 89] 
problem of the origin of life is not within range 
of solution. Special attention is devoted to the 
, Appendiculata, and particularly to Peripatus as 
| a connecting link between Annelids and Arthro- 
pods. The structure of Nebalia and Anaspides 
is discussed in reference to the light it throws 
on the course of crustacean evolution. The 
chief characters of several invertebrate larval 
forms are considered in regard to their bearing 
on the relationships of certain phyla to one 
another; in this connection Mr. Smith maintains 
that, although certain larval forms, e.g. the 
trochosphere and the nauplius, may be ancient, 
they are not to be regarded as representing the 
ancestral form of the phyla to which they belong. 
The annelid theory of vertebrate descent is dis- 
| cussed, and the difficulty of reconciling this view 
with the conditions present in Balanoglossus is 
pointed out, the origin of vertebrates being rele- 
gated by the author to the category of unsolved 
problems. Among other subjects treated in an 
interesting manner are the derivation of lungs 
from the air-bladder of Dipnoi, the rise of the 
mammals, and the degeneracy of marsupials. 
The volume brings into prominence the special 
features which have been found to throw light 
on phylogenetic problems, and is a good intro- 
duction to the mode of application of the com- 
parative method in morphology, and to some of 
the principal results obtained. 
| Micropetrology for Beginners. An Introduction 
| to the Use of the Microscope in the Examina- 
tion of Thin Sections of Igneous Rocks. By 
J. E. Wynfield Rhodes. With a preface by 
C. H. Sidebotham. Pp. xv+126. (London: 
Longmans, Green and Co., 1912.) Price 2s. 6d. 
| net. 
Tue object of this work, as stated by its author, 
is to supply teachers in evening technical schools, 
and others, with practical information on the use 
of the petrological microscope—so far at least as 
is necessary in the instruction of students in 
geology for the Intermediate B.Sc. of the London 
University. It is disappointing to find that a 
work of this kind is considered to be necessary, 
for it might fairly be hoped that teachers, under- 
taking the preparation of candidates for university 
degrees, would themselves have the necessary 
practical knowledge for the guidance of their 
students in manipulation—seeing that an ounce of 
showing is worth a pound of telling. 
So far as is possible in work of this kind, the 
practical directions given in the book are clear, 
and anticipate many of the difficulties that may 
arise. The weakest portion of the book is the 
second chapter, in which an attempt is made, in a 
few pages, to deal with the question of the 
optical properties of minerals. In the aim at 
condensation many unexplained terms are em- 
ployed, and not a few statements are made which 
are open to serious criticism. Much more suc- 
cessful is the latter portion of the book, in which 
a number of rock-sections are described and illus- 
trated; but as the selection of rocks is confined to 
