70 
THE SUBSTITUTE. 
thread it is easy to trace its course 
to the ground, and the poor larva 
becomes a captive. I have found 
this plan answer in most cases, 
and think others may derive bene- 
fit from it, as many a rare insect 
is lost by losing the larva. If you 
think this is worth inserting in 
the ‘ Substitute,’ you are at liberty 
to do so. — E. II. PiiiKST, 14, 
Parliament Street; November 22, 
1856. 
NEW BOOKS. 
Elements of Entomology; an 
Outline of the Natural History 
and Classification of British 
Insects. By W. S. D.vllas, 
F.L.S. Nos. 1, 2 and 3, 6d, 
each. Van Voorst, 1, Pater- 
noster Row. 
We have waited till this work 
was getting rather advanced, be- 
fore bringing it under the notice 
of our readers. It is never fair to 
judge of unfinished works; even 
now, who knows how far numbers 
11, 12 and 13 may disappoint the 
expectations we have formed by a 
perusal of numbers 1, 2 and 3. 
Besides, the opening chapters of 
all books are apt to be tedious. 
The novelist, to be sure, often ap- 
pears to avoid this, by commencing 
at the first start with some very 
animated conversation, and then 
after he has kept up the interest 
for some ten or twelve pages, he 
proceeds to tell you all the his- 
tories and antecedents of the per- 
sons whose conversation has al- 
ready interested the reader. But 
the writer of a scientific work conld 
hardly treat his subject in this 
way ; he muxt begin at the begin- 
ning, and so we presume Mr. 
Dallas thought, when he devoted 
his first chapter to the considera- 
tion of the enquiry, “ What is an 
Insect?” Having satisfied us on 
this head, he proceeds to give us a 
chapter “ Of the Structure of In- 
sects in general,” embellished with 
a wood-cut representing the head 
and mouth of a beetle. The 
mouth, in insects, as in most ani- 
mals, is an organ of great import- 
ance, and being the entrance 
through which the stomach re- 
ceives its supplies, is necessarily 
an important consideration in ani- 
mal economy. Almost every or- 
der of insects has the mouth con- 
structed in a different way, so that 
we really feel surprised to find 
how great is the variety of modi- 
fications which the same organs 
undergo, in order to fit them for 
obtaining nutrition for the insect 
from dead or living organizations, 
in a liquid or solid state. 
The next chapter introduces us 
to the “Sexes and Transforma- 
tions of Insects,’’ and though so 
much has been written about 
“ transformations,’’ and we have 
such excellent notices on this head 
in Kirby and Spence’s ‘ Introduc- 
tion to Entomology’ (which pro- 
bably, in its cheap form, is 
possessed by every one of our rea- 
ders), still, in a systematic work 
like this of Mr. Dallas, we do not 
see how he could have avoided 
some notice of that mystery in 
insect-life. 
Then follows a chapter of 
‘ Classification and Nomencla- 
ture,’ and we think we show no 
great amount of penetration, in 
prophesying that it will not give 
entire satisfaction to every one, 
but we do not think that this will 
