WESTERN SNEEZEWEED AS A POISONOUS PLANT. 29 



and an invasion of great numbers of leucocytes. The serum which 

 has become coagulated is in all tissues, pushing the tissue elements 

 apart and greatly thickening the walls. It is a portion of this serous 

 transudate which was found in the serous coat in the neighborhood 

 of the rumino-reticular groove. In these cases, with one exception, 

 erythrocytes are not abundant, though vessels just beneath the 

 mucosa are distended. 



The leucocytes are very abundant in the submucosa in places 

 and are grouped, resembling lymph nodules. These areas may ex- 

 tend up' through the muscular layers and into the serosa. The 

 cells of these areas differ from those of lymph nodules. They are 

 apparently more or less degenerated, but on the whole more re- 

 semble polymorphonuclear leucocytes than the cells of the lymph 

 nodules. The abomasum wall is edematous, and in areas in the mucosa 

 is sometimes hemorrhagic. 



Sheep 451, which was given an extract of Helenium hoopesii in a 

 drench, differed from the foregoing in that the point of irritation was 

 mainly in the abomasum, colon, and rectum. The walls of these por- 

 tions of the alimentary tract were highly congested, the congestion being 

 accompanied by edema and hemorrhage. This condition was most 

 pronounced in the mucosa in which layer degenerative changes had 

 occurred. The abomasum wall was most thickened and the serum 

 Was more coagulated there than elsewhere. The condition differed 

 from that found in the first and second stomachs of the force-fed cases 

 in that there was not so marked an invasion with leucocytes; more 

 blood was present, and the serum was less coagulated. In this case 

 the duodenum and jejunum were quite edematous but not severely 

 congested. No sections of the ileum were made, though the autopsy 

 report shows it to have been inflamed in portions. 



This inflammation of portions of the alimentary tract does not 

 occur in chronic cases. There may be mild congestion and some 

 edema present in the abomasum and ileum, but this is not severe. 

 In many places in the digestive tract the erythrocytes of the venous 

 blood take the eosin stain much less strongly than those in the neigh- 

 boring arteries. This, taken with the finding of degenerated erythro- 

 cytes in the veins of the liver, indicates a certain amount of direct 

 action of the toxin on the red blood corpuscles. That this is not 

 severe in chronic cases has been shown by hemoglobin tests on sick 

 as compared with normal sheep. 



Tissues from a number of guinea pigs killed or made sick on extracts 

 of Helenium hoopesii were studied and agreed fully with the findings 

 on sheep tissues. 



Dugaldin, thenj appears to be highly irritant and to be absorbed 

 in any portion of the alimentary tract of the ruminant. It is proba- 



