30 BULLETIN 800, U. S. DEPARTMENT OF AGRICULTURE. 



interlobular connective tissue and the medullary portion of the 

 lobules being more hemorrhagic than congested. The blaod in these 

 areas obscures the tissues of the gland. The thymus tissues of the 

 steer are not congested, but have been invaded by numerous eosino- 

 phile leucocytes. 



NERVOUS SYSTEM. 



The following portions of the central nervous system have been 

 studied — cerebral cortex, cerebellum, hippocampus, medulla, and cer- 

 vical and lumbar cords. In all parts there is a fullness of the capilla- 

 ries which in some cases, especially in the spinal cord, is congestion 

 rather than fullness. The varying condition found is simply one of 

 degree. The most marked pathological condition found is in the 

 cervical spinal cord of Sheep 492. In these sections there is pro- 

 nounced capillary congestion, especially of the gray matter, with 

 areas where hemorrhages have occurred. The perivascular and peri- 

 cellular lymph spaces are much distended, as is the central canal. 

 This condition exists in most of the sections of the central nervous 

 system examined which included tissues from 4 sheep and 1 guinea 



pig- 



LIVES. 



The only change characteristic of Asclepias poisoning noted in the 

 liver is a slight though well-marked cloudy swelling of the hepatic 

 cells. 



ALIMENTARY CANAL. 



In the abomasum and intestines of the sheep and the steer the 

 changes as a rule are not severe. They are largely vascular and in 

 most cases vary from fullness to mild congestion. Here the effects 

 of the high capillary pressure are well shown in the unusually full 

 and prominent capillaries in the muscular layers. These vascular 

 changes are perhaps most marked in the ileum, but while of the same 

 general character, in some instances a well-marked congestion, with 

 edema and diapedesis of red blood cells, also exists in the mucosa. 

 In the mucosa of the ileum of the steer there is besides the unusual 

 number of red blood cells a very pronounced invasion of eosinophile 

 cells. In some cases there is a marked excess of polymorphonuclear 

 leucocytes in the mucosa. 



SPLEEN. 



Changes in the spleen were not so pronounced as in the tissues 

 previously mentioned. They consisted of a possible distention of a 

 few cavernous veins and a few small areas of congestion and some- 

 times the presence of considerable blood pigm.ent. Guinea pig 35 

 was of interest, as many of the endothelial cells show their phagocytic 

 function containing one or more red blood corpuscles and indicating 

 a certain degree of blood destruction. 



