298 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



T^ARKSPUR POISONING. — Work Oil tliis important source of loss in the 

 West has been continued at Baldwin, Colo. The main characteristics 

 of (lie action of the various sorts of larkspur have been fairly well 

 dov('lo])e(l and rcMuedial measures have been sought with an encour- 

 aging degree of success. 



Cooperation with the Forest Service. — The important line of 

 work in cooperation with the Forest Service has been continued. An 

 additional number of forests have been visited and the probable 

 cause of trouble on account of poisonous plants in many places has 

 been ascertained. In consultation with Forest Service officers, means 

 of reducing the chances of loss have in some places been put into 

 operation. 



Eelation of corn to pellagra. — An investigation of the relation 

 between the spoiling of corn and the occurrence of the disease known 

 as pellagra has been undertaken by Dr. C. L. Alsberg and Mr. O. F. 

 Black. The connection of spoiled corn with this disease has often 

 been asserted or denied. Since this question affects one of our staple 

 agricultural products, which is likewise an important item of com- 

 merce, this problem becomes one of great importance. As the con- 

 stituents of unspoiled corn seem never to have been adequately 

 studied, the investigation has of necessity taken a rather wide range. 

 A paper of a somewhat popular character has been prepared con- 

 cerning spoiled corn and the methods of detecting deterioration. 



Miscellaneous laboratory avork. — Many inquiries have been re- 

 ceived concerning the possible poisonous properties of the "wonder- 

 berry " and related solanaceous berries, wdiich have been the subject of 

 considerable public interest, and preliminary investigations on this 

 subject have been undertaken. 



The products developed in culture media by bacteria parasitic on 

 plants have been investigated in cooperation with Dr. Erwin F. 

 Smith, Pathologist in Charge of the Laboratory of Plant Pathology, 

 a brief paper on the production of gluconic acid by the olive tubercle 

 organism having been prepared. 



It not infrequently hajDpens that crude drugs of native origin, col- 

 lected by untrained people, become confused, and a careful study of 

 the plants concerned is required in order to ascertain the real condi- 

 tion of affairs. The crude drug "yam root," or " Dioscorea," having 

 come into this confused condition, a study of the whole group of the 

 Dioscorea? of this country has been made by Mr. II. H. Bartlett, 

 Chemical Biologist, and the difficulty solved. A bulletin presenting 

 the results has been prepared. 



GENERAL PHYSIOLOGICAL INVESTIGATIONS. 



Various problems of a general physiological nature, bearing upon 

 the handling and keeping of different crops, have continued to receive 

 attention and good progress has been made along several lines. 



Physiological studies on truck and other crops. — The difficulty 

 of successfully storing sweet potatoes, onions, and certain other 

 vegetables has led to an investigation by Dr. H. Hasselbring, Physi- 

 ologist, of the physiological conditions involved in such storage and 

 in the decay which so often leads to heavy losses. Work on the sweet 



