_Protection from Insects and Diseases._ In coöperation with the Bureau of Entomology and the Bureau of Plant Industry the Forest Service is conducting a large number of studies and investigations dealing with the insects and diseases that do destructive damage to forests. The direct result of these studies will be the gradual eradication of predaceous insects and dangerous tree diseases from the valuable timber forests of the Government. Control measures already taken have shown the value of exact scientific information. On the Klamath National Forest some years ago about 900 acres were treated for insect infestation. The cost was about $3,000 and the amount of timber saved by the eradication of the insects was worth over $600,000. Other studies are carried on to identify and describe certain classes of insects, such, for instance, as those that destroy the seeds of trees in the cones. The various families, genera, and species of forest insects are studied and described, and the results are published in the form of monographs. Many of these insects are difficult to identify and concerning others very little is known. Investigations on tree diseases have not made such good progress, because tree diseases are much more difficult to control. Tree diseases, like human diseases, must be prevented instead of controlled. A general survey of the tree diseases prevalent in the National Forests has been made, especially in California. Further studies have brought to light little known or even unknown diseases. In California, studies have shown that a certain relation exists between old age and disease. Incense cedar, for example, seems to become infested after it reaches maturity at an age of about 150 years.