INSECTA, 
189 
INSECTA 
BY 
W. S. Dallas, F.L.S., M.E.S. 
A. Separate Works. 
Boisduval — . Essai sur PEntomologie horticole, comprenant 
FHistoire des Insectes niiisibles h F Horticulture, avec Fin- 
dication des Moyens propres a les eloigner on h les de- 
truire, et FHistoire des Insectes et autres Animaux utiles 
aux Cultures. 8vo, pp. 648. Paris, 1867. 
In this work Boisduval describes, in a semipopular manner, 
the various insects which are injurious to horticulture, inclu- 
ding under the term insects all the Arthropod classes of which 
representatives are found in gardens. The quality of the work 
is not very high, yet it will be useful not only as a guide to the 
gardener in combating his insect foes, but as furnishing a con- 
siderable mass of general entomological information, illustrated 
by examples taken from among our commonest and most 
accessible insects, such as may serve greatly to assist the be- 
ginner. The lower forms of the Rhynchota {Aphides and Coc- 
cidee) are treated by the author at greatest length. 
Newman, E. Tlie Insect-Hunter^s Year-book for 1867. 8vo. 
London : ]?]. Newman, March 1, 1868. 
This work is said by its author to be an attempt to establish 
a chronological and systematic record of discoveries and ob- 
servations in British Entomology, a purpose which seems to 
have been already pretty well fulfilled by StaintoiFs ^ Entomo- 
logist’s Annual.’ It includes only Lepidoptera and Coleoptera. 
The majority of the species referred to are briefly characterized. 
Wagner, Moritz. Die Darwin’sehe Thcoric und das Migra- 
tionsgesetz der Organismen. 8vo, pp. 62. Leipzig, 1868. 
The author cites numerous instances to prove that in order 
to account for the production of new species by the operation of 
the laws embraced by Darwin under the general term natural 
selection,” with the assistance of the struggle for existence,” 
another law is necessary, namely, the law of migration of or- 
ganisms.” Migration may be active or passive : the former 
1868. [voL. V.] p 
