BUREAU OP ANIMAL INDUSTRY. 151 



held at a temperature not higher thari 5° F. not less than 20 days). 

 This class is released from further special supervision after stuffing. 



Class B. — Sausages or chopped meats that contain lean fresh pork 

 and that are to be held under supervision after stuffing during the 

 process of drying (20 to 25 clays) in the drying room. 



Class C. — Sausages or chopped meats that contain lean fresh pork 

 and that are to be subjected to sufficient heat after stuffing to destroy 

 the vitality of any trichinae that may be present. 



It has been found at Chicago that this method of classification 

 renders the task of supervising the preparation of such sausages 

 much simpler, and it is recommended for general adoption at all 

 bureau stations, especially at those stations where from time to time 

 different inspectors are assigned to the same department of an estab- 

 lishment. Any inspector can then readily determine what further 

 processing is necessary in order to conform to bureau requirements 

 in the case of any given lot of product in course of prepartion in the 

 department to which he is assigned. 



During the year a report of investigations on the effects of heat 

 on trichinse was published in the Journal of Agricultural Research, 

 and Department Bulletin 880, on the effects of pork-curing processes 

 on trichinae, was in the final stages of printing at the close of the 

 fiscal 3'ear. A report of the effects of X-rays upon trichinae has also 

 been prepared for publication. 



MISCELLANEOUS INVESTIGATIONS ON ANIMAL PARASITES. 



Investigations on the possible relations between swamp fever in 

 horses and intestinal parasites, in cooperation with the Health of 

 Animals Branch, Canadian Department of Agriculture, have been 

 continued. The investigations on the gapeworm of chickens have 

 been continued. 



It has been discovered that a small roundworm {Coo2)eria punc- 

 tata) which is of common occurrence in the small intestine of cattle, 

 especially in the southern part of the United States, has the habit, 

 not previously recognized, of penetrating into the wall of the small 

 intestine, where it causes considerable disturbance in the tissues and 

 brings about an accumulation or proliferation of lympoid elements, 

 the lesions often being noticealjle through the serous coat of the 

 intestine as small yellowish spots either isolated or arranged in 

 groups. The upper portion of the small intestine only is involved so 

 far as yet observed. In affected portions of the intestine the wall 

 is usually thickened. It is not unlikely that this small and incon-' 

 spicuous parasite, which is often present in the lumen of the intestine 

 in enormous numbers, may prove to be an important factor in the 

 losses caused by internal parasites of cattle. 



A study of the life history of the hookworm of cattle {Bunostomum 

 flilebotomiuiii) is in progress. The investigations concerning toxic 

 substances in parasitic worms have been continued. The hemolytic 

 substances in Ascaris have been found to be completely soluble in 

 alcohol, thus disproving the view that fatty acids in the body of 

 Ascaris are responsible for their hemolytic action. Hemolytic sub- 

 stances have been discovered in the hookworms of cattle (Bunosto- 

 tnuin 2)hlehotoinum) and of dogs {Ancylostoma caninum), and in 

 whipworms {Trichuns spp.), but as yet no toxic substances have 



