278 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



investigated in a botanical way. In general it has been relatively 

 easy to point out the plants which are likely to be troublesomej and 

 in many cases it has been possible to suggest methods of avoiding 

 losses of live stock. Sometimes a change of trail is suflicient to help, 

 at other times a change in the season of mazing certain areas. Where 

 the oiFending plants are not too abundant it seems feasible to dig 

 them out. The work has been greatly facilitated through the full 

 and helpful cooperation of the Forest Service. 



Relation of corn to pellagra. — The study of spoiled corn has 

 been continued with new and interesting results. Such molds as are 

 likely to appear on corn have been studied, in cooperation with Dr. 

 Erwin F. Smith, pathologist, and the substances formed by these 

 corn-infesting molds have been submitted to biochemical and physio- 

 logical investigation. As a result certain molds found on corn have 

 been found to develop toxic products on corn-culture media as well 

 as on other media. While it is not yet demonstrated that these molds 

 stand in immediate causal relation to pellagra, an important possi- 

 bility is suggested. 



Methods of testing spoiled corn for products of deterioration have 

 been developed on a practical basis and laboratory methods have 

 been devised and made available by publication which have been 

 adopted in food investigations both in the department and in the 

 organizations of different States. 



Miscellaneous poisonous-plant work. — During the year the 

 usual number of inquiries have been received concerning the possible 

 poisonous properties of a large number of plants. The occurrence 

 of prussic-acid poisoning has received some attention, it being thought 

 possible that several plants not now regarded as harmful might be 

 possible sources of this trouble. Although in most cases negative 

 results have been obtained, the demonstration of this active poison 

 in others has seemed to warrant a wider extension of the work, which 

 it is hoped may be taken up during the coming fiscal year. The 

 occurrence of an outbreak of sheep and cattle poisoning near Wil- 

 mington, N. C., supposed to be due to Amianthhim muscaetoxicnm or 

 fly poison, locally known as " stagger plant," was investigated in the 

 laboratory. A small amount of material obtained for experiment 

 gave evidence of toxicity. Demands upon the office elsewhere ren- 

 dered it impossible to press the investigation as fully as its im- 

 portance seemed to warrant, but it is hoped that more complete re- 

 sults may be obtained during the coming season. A number of other 

 plants suspected of causing losses by poisoning in the East have been 

 examined and further investigations are planned. 



PHYSIOLOGICAL AND FERMENTATION INVESTIGATIONS. 



' Physiological studies. — The vegetable storage work carried on by 

 Dr. Heinrich Hasselbring has been continued in cooperation with 

 Prof. L. C. Corbett, horticulturist, and results of importance in con- 

 nection with sweet potatoes have been obtained. It appears probable 

 that physiological factors play a very important role in bringing 

 about the rapid decay of this important product, and it is hoped that 

 through a better understanding of the conditions methods of decreas- 

 ing these losses may be developed. In cooperation with the Office of 



