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REVIEWS OF NEW PUBLICATIONS. 
membrane into a thicker fluid, and in all such cases, as circumstances may 
happen, will there be an inflow termed Endosmose^ or an outflow, Exosmose^ and 
which depends upon electrical agency. So in the cases of plants, he supposes 
that the spongioles of the roots contain a thicker fluid than that they imbibe, 
and that, by a similar action to the one above mentioned, it is forced upwards. 
But this interesting question is still unsettled, and its causes are as little satis¬ 
factorily shown as those influencing the descent of the pulp.—W. R. S., Doncaster, 
Aug, 11, 1837. [[Further observations will be published on this subject in our 
next.—E d.] 
REVIEWS OF NEW PUBLICATIONS. 
A Guide to an Arrangement of British Insects: being a catalogue of all the 
named species hitherto discovered in Great Britain and Ireland. By John 
Curtis, F.L.S., &c., &c. Second edition, greatly enlarged. London: Pigot and 
Co., Fleet-Street, 1837- 
This is the latest and best catalogue of native insects extant. It has evidently 
been compiled with great care and labour; and the entomologist in possession of 
the first edition will quickly find that the “ greatly enlarged,” on the title-page 
of the present impression, is not a mere catchpenny. Not the least important 
improvement is the addition of the alphabetical index of genera, the want of 
which we have often felt in the previous edition. Every student is aware of the 
very large number of genera in British Entomology, and this may frequently 
prove a stumbling-block even to the proficient in the study, without a well- 
arranged index to the genera. 
The author has the follovnng considerations in view in offering his Guide to 
British entomologists :— 
‘‘ 1st. It will enable them to arrange their cabinets systematically. 
“ 2ndly. They may mark off their own insects so as to know instantly 
whether they have a species or not, by which means their desiderata will be 
shown; and this the author is persuaded will enable students to enrich their 
cabinets, by mutual exchanges, to an extent which could not be accomplished 
by any other means. 
“ 3rdly. It will form labels for cabinets. 
“ 4thly. It will be a systematic index to the British Entomology, a reference 
being given to every genus already illustrated, and may easily be continued by 
those who are desirous of completing it. 
