LOCOWEED DISEASE OF SHEEP 389 



composed of dense masses of lymphoid cells except that here and there a germinal cen- 

 ter stood out as a pale pink focus in the cortex. All of the central sinuses were very 

 widely dilated and contained free cells. The cell columns were reduced corresponding 

 to the dilatation of the sinuses. Under high power the center of one of the germinal 

 centers showed a moderately large amount of slightly stringy, rather homogeneous 

 deep pink hyaline material in which were only a few cells ; around these were a number 

 of large, vesicular nuclei, oval or round, which formed several layers not sharply 

 marked and mixed more and more with lymphoid cells as one passed from the center 

 to the periphery. Small masses of- interstitial hyaline were also found in the cortex 

 elsewhere than in the cell nests. The cells in the dilated sinuses appeared to be large 

 desquamated epithelial cells which were often phagocytic. The sinuses also contained 

 a moderate number of polymorphonuclear eosinophiles and lymphoid cells. 



Section through a small hemolymph gland about 3 mm. in diameter showed that 

 the peripheral sinus was dilated and packed with red cells, the central sinuses were 

 not nearly so dilated as in the cases previously recorded but most of them were packed 

 with red cells. A distinction into germ centers and cell columns could not be made out, 

 the section appearing to be made of the sinuses distended with red blood cells and of 

 intervening diffuse, cellular tissue in which a light reticulum could be made out. 

 As seen under the high power, the cellular tissue seemed to be chiefly made of cells 

 of a lymphoid type and of variations from this type. Endothelial cells phagocyting 

 red corpuscles were common. Bone marrow showed an increase in polymorphonu- 

 clears, many of which were eosinophilic, and an increase in cells of the myelocyte 

 type. Section through the thyroid showed a number of acini containii;g bluish pink 

 secretion, the acini being lined by vacuolated cuboidal or low columnar cells. There 

 were many small acini. 



Anatomical diagnosis. Thysanosoma actinioides infection; abscess of liver with 

 sub-diaphragmatic abscess; fibrosis in liver; vacuolization of pancreas cells and kid- 

 ney; emaciation; loose and irregular incisor teeth; verminous pneumonia, Strongylus 

 {Meta-strongylus) filaria; Sarcocystis tenella. Lymphadenitis. 



Partial autopsies were performed upon three of the healthier invalid lambs on 

 Mr. Cliff Kelly's ranch. All three died from experimental doses of cavadine (death 

 camus) administered by Professor Chesnut. 



Autopsy No. 5. This animal was infected with Thysanosoma aclinioides and 

 showed a small caseous-cystic cavity in the apex of the right lung. 



Autopsy No. 8. The fringed tape-worm was present in this animal also, together 

 with organizing bronchopneumonia, and sarcosporidiosis. 



Autopsy No. 7. No worms were found in a partial autopsy of this animal. Micro- 

 scopically, there were great numbers of sarcocysts in the heart muscle and diaphragm. 



Case No. 8. October 15, 1903. Mr. Clifford Kelly's ranch. A number of badly 

 diseased sheep, regarded as cases of "loco" were confined to a pen and fed with loco- 

 weed for a short while. One was examined, which had been fed for two weeks on 

 freshly plucked locoweed, occasionally receiving also a little alfalfa. Before autopsy 

 it was observed that there were no special symptoms. Pupils were not dilated nor 

 contracted. The animal presented exactly the same features as the other animals 

 which had not been fed on loco. It ate by preference alfalfa but also ate the loco 

 which was put in the corral. Animal emaciated and stiff. Bled from carotid, skinned, 

 and autopsied at once. 



Autopsy No. 8. Very much emaciated animal. Fleece rough and poor. Subcu- 



