BUREAU OF ANIMAL INDUSTRY. 115 



response to subcutaneous allergic tests. Neither specific comple- 

 ment-fixing bodies nor agglutinins can be detected in the sera of 

 affected animals. A paper reporting this work has been prepared 

 for publication in the Journal of Agricultural Research. 



DISEASE OF EYES OF CATTLE. 



A disease of the eyes of cattle appeared in the summer of 1917 on 

 a farm in Maryland. The history of the outbreak showed that after 

 the first few animals had been affected for a short time the disease 

 spread rapidly, or within two days, to other lots of cattle, some of 

 which were at a distance from the ones first attacked. 



The disease was characterized by a profuse flow of tears, followed 

 by cloudiness of the cornea and the development of ulcers upon the 

 surface of the cornea. In the progress of the disease the cornea 

 became o])aque, and in the v/orst cases the whole eye seemed involved, 

 resulting in total blindness in one or both eyes. 



Many attempts to isolate a pathogenic organism from the eyes of 

 the affected cattle were made, but without success. It was found to 

 be impossible to transmit the disease to healthy cattle or to labora- 

 tory animals by means of inoculating them with any of the bacteria 

 recovered from the diseased eyes. 



In treating the affected eyes the best results were obtained from 

 a 1 per cent solution of silver nitrate applied to the eye gently with a 

 soft cotton swab every second day until there was noticeable improve- 

 ment and every fourth or fifth day thereafter until the eye became 

 clear or free from the inflammation. 



INFLAMMATION OF THE JOINTS IN SWINE. 



Enlarged and inflamed joints (arthritis) of swine have been found 

 often in the course of meat-inspection observations, and when the 

 diseased joints are those of the hams or shoulders the loss in meat food 

 products becomes of some importance. Investigations of the condi- 

 tion have therefore been made. 



A large percentage of the joints examined contained a smaU Gram- 

 positive red-shaped organism which resembles Bacillus 'pyogenes in 

 morphology but differs from it in a few cultural characteristics. 

 Results of experiments indicate that this unidentified organism is a 

 causative factor of the arthritis. A pig inoculated intravenously 

 with a pure culture of the organism on two occasions developed 

 arthritis with distention of the synovial capsule, a condition typical 

 of the early stages of the natural disease, and a pure culture of the 

 organism was recovered from the lesion. Similar inoculation of grown 

 hogs yielded negative results, older animals seeming more resistant 

 to the infection than pigs one or two months of age. Rabbits were 

 also infected by inoculation. 



IMPROVED METHOD IN COMPLEMENT-FIXATION TEST. 



The Pathological Division has devised an improved method for 

 recovering trypanosomes from the blood of rats for antigen purposes 

 in connection with the complement-fixation test which is used in the 

 diagnosis of several diseases. A description of this method has been 

 prepared for publication in the Journal of Agricultural Research. 



