10 BULLETIN 969, TT. S. DEPARTMENT OF AGRICULTURE. 
In one animal congestion was present in the duodenum, jejunum, 
and ileum; in another this condition was found only in the ileum 
and cecum; while the third had a hemorrhagic area in the duodenum 
and minute hemorrhages in the ileum. The pancreas was congested 
in one. The livers of two were noted as pale. The kidneys were 
congested in one and hyperemic in another. 
In general, the autopsy findings corresponded very well to 
those seen in animals poisoned by the other whorled milkweeds. 
PATHOLOGICAL CHANGES IN TISSUES. 
The autopsies in 2 of the 3 sheep killed with Asclepias mexicana 
in 1920 were commenced within 30 minutes after their deaths. 
These were Sheep 590 and 595. Sheep 610 was dead much longer be- 
fore the autopsy and well-marked post-mortem changes had occurred 
in the tissues. The following description of the pathological changes 
is based on Nos. 590 and 595. The material was fixed in 10 per cent 
formalin and stained with Delafield's hematoxylin and eosin, except 
specimens of the cerebellum of Sheep 590, which were fixed in alcohol 
and stained with various nerve-cell stains. Formalin-fixed material 
of the cerebellum of both sheep was stained with toluidin blue, Nissl 
stain, polychrome methylene blue, neutral red, and other stains. 
Liver. — The hepatic cells in both animals had undergone well- 
marked degenerative changes which differed slightly in the two 
cases — those of Sheep 590 were very fatty, the nuclei, however, 
taking the stain well, while the hepatic cells in the liver of Sheep 
595 had a very granular and swollen cytoplasm. In the liver of 
Sheep 595, too, certain hepatic cells, singly and in groups, showed 
marked affinity for eosin. In the capillaries of the liver lobules of 
both there was an unusually large number of leucocytes, especially 
polymorphonuclear. These were often in small clumps, covering 
the area of half a dozen or more hepatic cells in the liver section 
of Sheep 590. 
The livers of both animals had congested and edematous areas 
with some small hemorrhages. This was most noticeable in one 
preparation of the liver of Sheep 590, where the congestion was 
severe just beneath the capsule and had compressed the liver cords. 
Many veins, both portal and hepatic, were empty, while others 
contained much granular detritus, brownish pigment granules, de- 
generate erythrocytes, and sometimes endothelial cell nuclei and 
numerous leucocytes. Rarely hepatic cells were found in the sub- 
lobular veins. The wall of the congested portion of the common 
bile duct- in both cases had undergone necrotic changes extending 
well into the mucosa. The epithelial layer was gone. 
Kidneys. — -In both kidneys there was congestion of the straight 
veins of the medulla and areas of capillary congestion in the cortex 
with a few small hemorrhages betweeen the tubules. The principal 
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