868 The American Naturalist. [September, 
Outlook for Economic Entomology.—An interesting article 
upon this subject, by Dr. C. V. Riley, is published in the American 
Garden for July, 1890. The author says: ‘‘ All late advances in the 
study, and all probable advances in the immediate future, come under 
three chief categories: (1) The ascertaining of every detail in the life- 
history of species at present injurious, or likely to become injurious. (2) 
Thorough and careful experiments with insecticide substances. (3) The 
invention and improvement of apparatus for the application of insecti- 
cides. . . . Asoneof the immediate results of the great increase in the 
number of paid entomologists who are able d — m or nearly all of 
their time to the work,consequent on the tof the State 
Experiment Stations, we may expect, after a little preliminary repeti- 
tion of previously known facts and remedies in the interest of accessi- 
bility, great advance along the lines of our first category. Our knowl- 
edge of the life-histories and habits of ail plant-destroying pests should 
take great and immediate strides, and, as I have shown, new prevent- 
ives and remedies will undoubtedly result from the establishing of facts 
_ of this character. Progress in the second and third categories will be 
much slower. Yet we may confidently anticipate advances in the 
cheapening of insecticides, and in better knowledge of their properties 
and the conditions governing their application. We may as confi- 
dently look for cheaper and better apparatus, though radical and 
important: discoveries in io direction are hardly to be anticipated, 
however much hoped for 
Recent Literature.—One of the most useful volumes ever pub- 
lished by the Department of Agriculture has lately been issued by the 
Bureau of Animal Industry. It is by Dr. Cooper Curtice, and is 
entitled, ‘The Animal Parasites of Sheep." There are 221 pages 
and thirty-six plates, the latter being well-executed lithographs from 
drawings by Haines and Marx. As Dr. Salmon well remarked in his 
letter of transmittal: ‘* The subject of parasites and parasitic diseases 
is one of great importance, and must become more prominent as the 
number of domesticated animals in the country increases, and the 
pastures become more limited in comparison with the flocks which 
graze upon them. Under such' conditions parasites multiply more 
rapidly, and their ravages become more alarming. For this reason 
e time has come when we must pay more attention to these organ- 
isms, and study more assiduously the means of controlling them, if we 
would preserve that healthfulness and vigor for which the animals of 
this country have heretofore been noted." 
