30 
be deduced from the actual vocabularies given. 
Personally, I should have been inclined to regard 
Yala (which is one amongst Koelle’s many in- 
teresting vocabularies of 1854, hitherto difficult 
to locate geographically) as having nothing to 
do with Edo, but much with the more ‘“semi- 
Bantu’ speech contiguous to it on the east. Not 
the least interesting part of this useful manual is 
the identification and location of eighteen of 
Koelle’s vocabularies, work which greatly en- 
hances their value to the philologist. In addition, 
Mr. Thomas introduces us for the first time to 
several speech forms—languages and dialects— 
hitherto unknown. 
Mr. Thomas’s work throws a good deal more 
light on the semi-Bantu languages in addition 
to the not-sufliciently-known work of Mr. P. 
Amaury Talbot. The analysis of the material 
his vocabularies furnish induces me to account 
for the semi-Bantu group and cognate languages 
in two ways:—Some of them, especially in the 
east and south of their range, may: be simply 
much-worn-down and corrupted real Bantu; 
relics of the comparatively ancient east-to-west 
migration, which finally carried a Bantu speech 
to the Island of Fernando P6. But the balance 
of probability, especially in regard to the more 
northern groups of semi-Bantu, lies in the direc- 
tion of their being descended from sister lan- 
guages of the original Bantu mother tongue. 
They would thus have migrated from north-east 
to south-west. All such indications seem to lead 
to the theory that the original home of the Bantu 
was somewhere in the very heart of Africa, be- 
tween the basins of the Benue, the Shari, the 
Mubangi and the Bahr-al-Ghazal. But Mr. 
Thomas’s work further directs our attention to 
the existence of Bantu roots in Ibé and Gori; and 
this ancient Bantu influence can, I believe, be 
traced much farther to the west than the lower 
Niger. H. H. Jounston. 
HOUSEHOLD INSECTS. 
(1) Insects the Household and 
Annoying to Man. By Prof. G. W. Herrick. 
Pp. xviit+470. (New York: The Macmillan 
Co. ; London: Macmillan and Co., 1914.) Price 
sSeOos Net, 
(2) The House-Fly, Musca domestica, Linn. Its 
Structure, Habits, Development, Relation to 
Disease and Control. By Dr. C. G. Hewitt. 
Pp. xv+382. (Cambridge University Press, 
Injurious to 
1914.) Price 15s. net. 
es OUSEHOLD insects” have, for many 
years past, attracted the attention 
of entomologists in North America, and since the 
publication of the well-known Bulletins of the 
NO. 2367, VOL. 95] 
NATURE 

[Marcu 11, 1915 
U.S. Department of Agriculture, by Dr. L. O. 
Howard and Mr. F. H. Chittenden, on pests of 
this nature, in 1896, much work of importance 
has been done, particularly with regard to house- 
flies and mosquitoes. Students of the subject 
should, therefore, be grateful to Prof. Herrick 
for providing a popular and trustworthy account 
(1) of our arthropodous “messmates”’ and para- 
sites. In addition to insects in the zoological 
sense of the term, spiders, mites, ticks, solpugids, 
scorpions, and centipedes are passed in review, 
and the British reader cannot but feel that some 
compensation for not being an American is 
afforded by the comparatively scanty house- 
fauna of his native land. 
The especial strength of Prof. Herrick’s book 
lies in the directions given for dealing practically 
with the various pests; systematic and bionomic 
considerations are, throughout the volume, sub- 
ordinated to the economic point of view. No 
fewer than one hundred pages are devoted to 
house-flies and mosquitoes; the disease-trans- 
mitting power of these insects is emphasised, 
albeit with the minimum of information as to the 
nature of the micro-organisms that they carry. 
Doubtless the author has been well advised to lay 
stress on the habits of the creatures that he 
describes in their relation to remedial and pre- 
ventive measures, but if a little more space could 
have been devoted to the zoological aspects of 
the subject, the reader would take a more intelli- 
gent interest in the practical problems brought 
to his notice. Each chapter is followed by an 
“economic” bibliography, and the book is illus- 
trated by more than 150 figures of somewhat 
unequal merit. 
(2) Dr. Gordon Hewitt has, by his researches 
since 1907, made the House-fly (Musca domes- 
tica), to an especial degree, his own subject, and 
his transference from Manchester to Ottawa has 
not cut him off from an abundant supply of mate- 
In the handy 
volume now before us, all the anatomical and histo- 
logical descriptions and figures from Dr. Hewitt’s 
previously published works are collected in a 
convenient form, and a full survey of the latest 
literature on the house-fly and allied Diptera, 
together with an account of Dr. Hewitt’s own 
recent investigations, will be found to furnish a 
store of information for the student. Interest in 
house-flies during recent years has centred around 
the possibility of these insects serving as carriers 
of disease-germs to human food-products, and 
the critical survey of the newest work on this 
subject—especially with regard to the prevalence 
of infantile diarrhoea during the fly season— 
forms a most valuable section of Dr. Hewitt’s 
rial of this cosmopolitan insect. 
