BOOK REVIEWS, 
453 
when their depredations exceed the limit of tolerance, and a few are 
systematic in their endeavours, many more take no steps at all 
towards checking them. This ought not to be, for in all these things 
general effort would be more effective than isolated. 
The present work, though American and therefore dealing with 
some insects which do not worry us here, and giving details of others 
which may not fit the facts entirely in this country, is yet a valuable 
work for the study and reference of all concerned in cultivating crops. 
It is well illustrated with figures of practically all the insects referred 
to, the figures being particularly clear. 
The insect is in each case described, an outline of its life-history 
and of its habits is given, the damage it does clearly indicated and 
frequently illustrated, and the methods suggested or already found 
successful in dealing with it are detailed. 
One instance of the fulness with which the last part is dealt with 
may be given in reference to the troublesome cabbage-root maggot, 
which causes so much loss in this country. To avoid infestation of 
the cabbages in the seed-bed, coverings of cheese-cloth may be used. 
The covers are to be removed ten days before transplanting, and if the 
small, but long, thin white eggs are observed during that time, trans- 
planting should be done at once. The placing of a hexagonal disc of 
tarred felt round the stem of each plant at ground -level after trans- 
planting is the surest method of prevention. 
A mixture of lime and carbolic acid may be applied to the surface 
of the soil (3 pints of lime slaked to a thin cream, diluted to 1 gallon with 
water, and a tablespoonful of crude carbolic acid added) about the 
plants. Kerosene and sand, gas tar and sand, tobacco dust, &c, have 
all been used to sprinkle about the plants. One part of gas tar (not 
more) to 25 parts sand is also said to be an effective mulch. Many 
methods of destroying the maggots are mentioned, but none so 
effective, says the author, as carbon bisulphide, which costs about 4s. 
for a thousand plants. 
All the more important insects are effectively treated, and the 
methods of control dealt with as fully as in the instance just quoted, 
with recipes where required, and very frequently with estimates of 
the cost of treatment as well. A few which we recognize here as very 
troublesome pests, including the apple sawfly, the pear midge, and the 
black-currant mite, are omitted, and presumably have yet to find their 
way over the Atlantic. 
" Insect Enemies." By C. A. Ealand, M.A. 8vo., xiii -j- 223 pp. 
(Grant Richards, London, 1916.) 6s. net. 
The long sub-title runs : " Enumerating the life-histories and 
destructive habits of a number of important British injurious 
insects, together with Descriptions enabling them to be recognized, 
and Methods by means of which they may be held in check.' ' 
