340 
IN ONIN MSIE 
[ FEBRUARY 7, 1907 
the figure of the Earth. The mathematical ingenuity 
exhibited may be interesting, but is familiar. In the 
form and to the extent in which the several problems 
are discussed, these chapters scarcely belong to a 
practical treatise, and do not afford the means of 
applying the facts that the student has himself derived 
from the use of instruments. 
In the second part, which consists of three chapters, 
the author serves up the standing dish of least 
squares. So far as theory is concerned he has fol- 
lowed Chauvenet, and for the practical application 
to triangulation and conditioned problems the admir- 
able treatise of Wright and Hayford on ‘‘ The Adjust- 
ment of Observations’’ (see Nature, vol. Ixxiv., 
p. 148). The book is well illustrated, and there are 
some useful tables and information given in an 
appendix, though we scarcely understand the prin- 
ciples upon which the formulae have been selected. 
The information throughout is conveyed in a clear and 
lucid manner, but a, little unevenness is sometimes 
noticeable, as though the author were uncertain of 
the degree of thoroughness with which the several 
topics should be treated. 
AN AMERICAN TEXT-BOOK OF 
ENTOMOLOGY. 
Entomology, with Special Reference to its Biological 
and Economic Aspects. By Dr. J. W. Folsom. 
Pp. vi+485; illustrated. (London: Rebman, Ltd., 
1906.) Price 14s. net. 
WORK treating of entomology purely from the 
bionomic and economic standpoints is a dis- 
tinct and long-felt want, but it cannot be said that 
the book under review supplies that want adequately, 
in spite of its title and a statement in the preface 
that it ‘‘ was written in an effort to meet a growing 
demand for a biological treatment of entomology.” 
With such admirable and detailed manuals of insect 
anatomy as Packard’s ‘“‘ Text-book of Entomology ”’ 
and Henneguy’s ‘‘ Les Insectes’’ already in the field, 
Dr. Folsom could have safely avoided a treatment of 
this subject; as it is, his second chapter, entitled 
“Anatomy and Physiology,’’ occupies nearly one- 
third of the book, and yet fails to attain the com- 
prehensiveness of the afore-mentioned manuals. 
Chapter vii., on the origin of adaptations and of 
species, might well have been omitted, for it contains 
nothing that is new and little that is not almost 
common knowledge; curiously enough, though 
de Vries’s work is discussed, there is no mention of 
Mendel or his followers. 
The inevitable result of these two unnecessary 
chapters is an unfortunate brevity of treatment in the 
more useful and interesting sections of the book, and 
many important phenomena and facts are crowded 
out altogether. The author may claim (as he does) 
that his work is “‘ concise,’’? but hardly that it is 
*“comprehensive,’’ since there is no mention of the 
life-history of Mantidz, of the eggs of Phasmide, 
of fig-insects, of the cuckoo-spit, of the formation of 
stick-lac, of the remarkable symbiosis of Acari and 
NO. 1945, VOL. 75 | 
bees of the genus Koptorthosoma, of the extraordinary 
beetles Mormolyce and Hypocephalus. The accounts 
of parthenogenesis, of phosphorescent insects, and of 
aquatic insects are lamentably brief, and nothing at 
all is said of the insects found in caves. 
Chapter ix., on insects in relation to other animals, 
is one of the best in the book; Dr. S. A. Forbes’s 
admirable reports on the insect food of birds and 
fishes have been largely drawn upon, and deserve. 
the attention directed to them. We have not noticed 
many errors, but the following need correction in a 
later edition:—Paraponyx is not the only lepidop- 
terous genus with truly aquatic larvae (p. 184); 
parakleta should be paralekta (p. 216); it is at least 
doubtful if the mimicry of bees and wasps by species 
of the genus Volucella can be classed under the head- 
ing of aggressive mimicry; it is far more probable 
that the flies secure immunity from the attacks of 
vertebrate foes by their resemblance to stinging 
insects than that this resemblance enables them to 
enter unobserved the nests of hosts who are quick 
enough to resist the intrusion of strangers of their 
own species (p. 235); the blood-parasite conveyed by 
Glossina morsitans is not similar to the malarial 
parasite (p. 306). The tsetse-fly is cited as the carrier 
of the blood-parasite in nagana disease, but not of 
the organism causing sleeping sickness. In _ the 
anatomical chapter some reference should be made 
to the fact that the stomodzeal and proctodzeal sections 
of the alimentary canal are lined with chitin, whilst 
the mesenteron, being of endodermal origin, is not. 
The numerous text figures are for the most part 
excellent, and a goodly proportion are original; 
special attention may be directed to Figs. 242 and 
260; the latter, if a genuine record of an actual 
occurrence, is a triumph of nature-photography ; 
Fig. 244, illustrating protective mimicry, is unfortu- 
nate, for it represents Eristalis tenax mimicking a 
stingless drone-bee. The coloured frontispiece is not 
only a poor example of what can be done in these 
days of improved methods of chromolithography and 
three-colour photography, but also abounds in errors, 
e.g. Fig. 1, labelled Heliconius eucrate, is Lycorea 
halia; Fig. 4 is not Mechanitis lysimnia, but Melinaea 
ethra; Fig. 5 is not Papilio merope g from South 
Africa, but Papilio antinorii 2 from Abyssinia ; 
Fig. 8 is Amauris echeria from West Africa, not 
from South Africa; Fig. 10 is not really like any 
butterfly known to science, but it apparently repre- 
sents Papilio merope, 2 form cenea, though it is 
labelled Amauris echeria, the ‘‘ model’’ of the Papilio 
mimic; Fig. 11, labelled Papilio merope 9, is appar- 
ently P. echerioides 9. This gives a total of six 
errors in eleven figures! It is evident that the author 
has reproduced the errors occurring in the plates 
illustrating Weismann’s ‘‘ Evolution Theory,’’ and it 
is a pity that, in the case of the African butterflies at 
any rate, he did not consult Trimen’s classical paper 
or the frontispiece to Poulton’s ‘‘ Colours of 
Animals.”’ 
A useful bibliography and a trustworthy and com- 
prehensive index conclude the work. RES: 
