iS8s.] 
A naly ses of Books . 
103 
Report of the Entomologist of the United States Department of 
Agriculture for the year 1880. By J. H. Comstock. Wash- 
ington : Government Printing-Office. 
In the United States, much more than in any other country, the 
damage done by insects to various crops is being closely scru- 
tinised, and the habits of these destroyers are carefully studied 
with a view of finding out means of limiting their ravages. 
Whether this judicious activity is due simply to the practical 
good sense of our Transatlantic neighbours, or is forced upon 
them by the fecundity of certain insect species under their warm 
summer suns, it is not necessary to inquire. But we may safely 
assume that the investigations of Mr. Comstock and his col- 
leagues will be of great service to agriculture all over the world, 
besides bringing in a rich harvest of purely scientific observa- 
tions. One of the facts most frequently forced upon the mind, 
in reading these reports, is the mutability of animal habits. 
Closet-naturalists of the old school, and even some out-door 
observers who confined their researches to some limited sphere, 
always tell us that every animal species is placed by Nature in 
the locality best suited to its existence and propagation, and that 
its choice of di et and general habits are dependent upon primor- 
dial and unvarying instindfs. In contradiction to such statements 
we find that a species on finding its way into some new region 
flourishes and multiplies to an extent unknown before. An 
insect may have long been recognised in Europe as practically 
harmless. Take it to America, and it may become a serious 
nuisance. 
In the volume before us a remarkable change of habits is re- 
corded in the scolytid beetle, Monarthrum fasciatum , which 
perforates the heads and staves of casks, letting the contents 
leak out. Formerly these enemies were kept at bay by painting 
the casks with white lead, but “ latterly they hardly wait for the 
casks to dry before commencing their attacks.” 
The greater part of this report is taken up with a thorough 
examination of the Coccidae, or scale-insedts, a tribe very 
destructive to vegetation in tropical and semi-tropical countries, 
and which are unfortunately cherished and defended by the ants, 
which even re-introduce them on trees where they have been 
destroyed. Mr. Comstock considers soap-lye the most effectual 
remedy. 
