184 ANlSrUAL REPORTS OF DEPARTMENT OP AGRICULTURE. 



Cooperation with the Bureau of Plant Industry in the study of 

 poisonous plants and means of reducing losses from them was con- 

 tinued at the field station near Gray cliff, Mont., and on various 

 Forests. Special attention was given to further work on death 

 camas and the lupines. It was definitely determined that death 

 camas is responsible for a great deal of loss from previously unde- 

 termined causes among sheep throughout the Northwest and on the 

 high summer ranges of the Utah Forests. It was established, also, 

 that lupine is the cause of a great deal of loss among sheep, and 

 that it is probably the cause of some loss heretofore unaccounted 

 for among horses. A good supply of forage, and quiet, open han- 

 dling of all stock are found of the first importance in eliminating 

 loss. In addition to the work on death camas and lupine, important 

 work was carried on with wild cherry, loco, sorghum, and to a small 

 extent with the laurels. It is now certain that all species of zyga- 

 denus except Zygadenus coloradensis are poisonous, and that all 

 species of larkspur are poisonous to cattle. Additional work will be 

 necessary on various species of lupine hitherto not studied. Work on 

 loco has been undertaken on comparatively few of the many species. 

 Minor investigations on the southwestern Forests suggest that species 

 hitherto little known as poisonous plants are probably responsible 

 for losses of stock on these Forests. In the latter part of the year 

 this work was transferred to the Bureau of Animal Industry. The 

 Forest Service cooperated with this bureau in selecting and estab- 

 lishing a new field station for poisonous-plant investigations on the 

 Fishlake Forest, in Utah, which will be used as a base of field opera- 

 tions in place of the Graycliff Station. Henceforth the Forest 

 Service will receive from the Bureau of Animal Industry informa- 

 tion as to the kinds of plants found to be poisonous to different 

 classes of stock and will then undertake to learn the distribution of 

 each species throughout the National Forests and to work out meth- 

 ods of protection. This problem has already been undertaken ag- 

 gressively. The main effort has been concentrated upon determining 

 the practicability of eradicating larkspur, both by grubbing it out 

 and by sheep grazing. A demonstration test to determine beyond 

 doubt the practicability of eradicating the larkspur is under way 

 now on a complete community cattle allotment on the Stanislaus 

 Forest. Kesults secured by grazing larkspur areas with sheep 

 before cattle are turned on are very promising. 



OTHER INVESTIGATIONS. 



SILVICULTURAL AND DENDROLOGICAL STUDIES. 



In tree studies work on seven species was completed. Continued 

 study of the woodlot problem, with particular reference to the mar- 

 keting of woodlot products, secured a large volume of data valuable 

 both for publications on woodlot handling and for demonstration 

 work in cooperation with State agricultural colleges. An economic 

 survey of the farm woodlots in the eastern United States was under- 

 taken in cooperation with the Office of Farm Management. Its aim 

 is to determine the economic value of the woodlot in the general 

 scheme of management adapted to the farm and to the particular 

 locality. 



Approximately 3,500 basket willow cuttings were distributed to 

 the State experiment stations, 400 to forest schools, and 14,900 to 



