OCTOBER 23, 1902] 
the sea or of volcanoes, is preserved among the rocks ; 
their record, indeed, is one of singular uniformity, despite 
the catastrophes of Krakatoa in Sunda Strait and of Ban- 
dai-san in Japan, to which attention is directed. Much has 
also been learnt about fissure-eruptions. Here we are in 
touch with the authors special subject, and he devotes 
a considerable space to the volcanic history of the British 
Isles. To petrography, which no doubt is dealt with in 
a special article, but brief reference is made. 
A glance at the article on geography shows how in- 
timately it has become linked with geology during the 
past quarter of a century, thanks to the labours of Suess, 
Penck, Lapworth and W. M. Davis. The fact that the 
surface of the sea preserves no uniformity, and that it 
may locally rise and fall to a considerable extent without 
change in the lithosphere, would seem to revolutionise 
our ideas about raised beaches and submerged forests ; 
but the author points to certain regions where there is 
definite evidence of slow upheaval or depression of land. 
The indications of changes of level derived from a study 
of coral-reefs are also discussed. 
Structural geology naturally occupies some space, 
and special reference is made to the great flexures and 
overthrusts that have been determined'in many regions. 
Paleontological zones receive attention, for on this 
subject great progress has been made, and although we 
miss reference to the brilliant researches of Dr. A. W. 
Rowe, the importance of the subject is fully admitted. 
We agree with the author that there is much yet to be 
solved in the problem of life-zones. Special mention 
might have been made of observations on radiolarian 
chert, but in so complex and many-sided a subject as 
geology wefeel that the author has done all that could 
well be done to illustrate its progress in a limited space. 
Prof. Greenhill’s two contributions on ballistics and 
the gyroscope and gyrostat are full of material of interest 
to students of dynamics. In a short essay Sir W. T. 
Thiselton-Dyer summarises the chief points of Huxley’s 
life and work, and contrives to express the essential 
characters of each in a few pages, Dr. Giinther has 
brought the article on fishes up to date. In 1870 the 
number of known species of living fishes was stated as 
8525, but since then it has been nearly doubled. Know- 
ledge of the distribution, organisation and development 
of fishes has also made substantial progress, and Dr. 
Giinther gives a survey of the most important advances. 
The article on insects is by Dr. David Sharp, whose 
general knowledge of the subject is probably more exten- 
sive than that of any other living entomologist. Neverthe- 
less, it is obvious that the space at his disposal was utterly 
inadequate to permit of his attempting more than a mere 
glance at a few of the more interesting matters connected 
with entomology that have been discussed in recent years. 
Among these are the number of species of insects ; an- 
tiquity ; duration of life (inadequately discussed ; but the 
fact ofa water-beetle living five and a half years in cap- 
tivity was new to us, though some of Lord Avebury’s Queen 
ants have attained a much greater age) ; economic ento- 
mology (with special reference to Coccidze, and to insects 
and malaria) ; luminosity (concerning which Dr. Sharp 
remarks, “ The light given by insects has been shown to 
be highly economical, and if a similar illuminating agent 
can be produced artificially it will be a great boon.” 
NO. 1721, VOL. 66] 
NATURE 
627 
Granted ; but then there is the immense initial difficulty 
of producing or imitating organic chemical substances 
artificially); galls; anatomy and morphology (with 
special reference to the structure of the segments of the 
head) ; metamorphosis ; classification (twenty-two orders 
are now recognised, the sequence of which differs con- 
siderably from that followed in the author’s ‘‘ Cambridge 
Natural History,” published in 1899) and ethology (re- 
ferring to intelligence and to social insects). The article 
concludes with a paragraph of “authorities,” including 
references to a few recently published books and papers 
on insects ; but the list 1s necessarily so short and in- 
complete that we think it might almost as well have been 
omitted altogether. 
Though limitations of space have prevented some of 
the writers from doing full justice to their subjects, the 
volumes are rich in matter of interest to the student of 
science, and furnish substantial evidence of progress 
in many branches of natural knowledge. 
THE STUDY OF THE PROTISTA. 
Archiv fir Protistenkunde. Herausgegeben von Dr. 
Fritz Schaudinn, Bandi. Heft 1. Pp. 192; 5 plates. 
(Jena: Gustav Fischer, 1902.) Price Mk. 24. 
F late years very rapid progress has been made in 
our knowledge of that vast assemblage of organisms 
for which Haeckel set up a special ““kingdom” or Reich 
with the name Protista, comprising the simplest living 
creatures amongst which the distinction of plant and 
animal is of quite secondary importance. Inno branch of 
biology do works become so quickly out of date as in that 
which deals with the lowest forms of life. The attention 
which the Protista have received has been stimulated 
from two sources. From a purely scientific and theoretical 
point of view, it is evident that many elementary problems, 
or fundamental phenomena, of life can be studied in their 
simplest form, divested of unessential complications, 
in these lowly organisms. This is especially true of the 
facts of cytology relating to the structure and activities of 
cells. The discoveries of the last decade of the nineteenth 
century have revealed a remarkable uniformity, under- 
lying the greatest variety in form and detail, in the cell- 
processes of the higher animals and plants, which cannot 
be considered as satisfactorily understood until the steps 
are made clear by which they have been evolved from 
the usually simpler, but in any case far more diversified, 
types of structure or development which are found to 
occur in unicellular organisms. It is only necessary to 
refer to the problems of cell-division and fertilisation in 
support of this proposition. Quite apart, however, from 
their claims on the attention of scientific biologists, the 
Protista are becoming continually more important as 
objects of study from the practical point of view, 
Some, as, for imstance, the organisms of fer- 
mentation, are indispensable for human arts and 
manufactures; others have a claim to consideration 
which, if more melancholy, is not less great, on account of 
the injuries or disease which they inflict as parasites or 
pathogenic agents upon man, beast, or plant. The im- 
portance of the lower organisms from the practical 
standpoint has already been the cause of specialisation 
in their study. An instance of this is seen in the rise 
