Bibliographical Notices. 380 
are sufficiently detailed, and treat separately of the different forms 
under which the species make their appearance; and they are 
founded, as already stated, upon the author’s own observations, 
which have been continuously carried on during many years in spite 
of physical disadvantages which it might be thought were hardly 
compatible with such labours. A few new genera are proposed by 
the author, sometimes, as it seems to us, upon insufficient characters ; 
but without a special knowledge of so difficult a group it is hard to 
form any sound opinion upon such a point as this. Undue multi- 
plication of genera is not by any means an unusual fault in zoolo- 
gical writers of the present day ; and it does not stand in the way of 
what, after all, is our author’s principal object, namely to enable 
students to determine the species of Aphides, and to give them a 
notion of the natural history of the insects. 
Besides giving a general account of the natural history of the 
group in his introductory chapter, the author indicates under the 
head of each species any thing that there may be peculiar in its 
habits and mode of life, and especially notes the injuries done to 
vegetation by the ordinate multiplication of some of the species. 
Further he mentions the various enemies of the Aphides, which 
serve more or less effectively to keep their multiplication within 
bounds ; and certain special sections of his book are devoted to the 
deseription of the habits of Aphidivorous groups of insects, such as 
the Hymenopterous parasites of various families, the fossorial Hyme- 
noptera, which provision their nests with Aphides, and the Hemero- 
biidee and Syrphid, whose larvee prey upon them. Throughout the 
book we find evidence of the most conscientious work; and this work 
has been directed to a most successful end. 
We have yet a few words to say about the illustrations, which 
are exceedingly numerous and characteristic. There are in all 114 
coloured plates illustrating the systematic part of the three volumes, 
besides three plates of anatomical details appended to the general 
introduction. The whole of these figures have been drawn by the 
author, the outlines being obtained by means of the camera lucida; 
so that their accuracy may be depended upon, although, perhaps, 
we miss that elegant arrangement of the limbs to which one is accus- 
tomed in entomological plates. As a matter of course the possession 
of such a quantity of reliable figures will facilitate in no small 
degree the identification of the species described ; and for their pub- 
lication we have to thank the Ray Society, seeing that, in all proba- 
bility, no publisher would embark his capital in such a risky under- 
taking. It isin the production of illustrated works like this that 
such societies as the ‘‘ Ray” find their raison détre; and it is a 
matter for regret that this valuable institution, which has already 
published so many important works, should at present be in a some- 
- what languishing condition for lack of subscribers. 
