l::<2 \i-:terin \R\ I'atiiology. 



ing acidophile granules), appear early in an inflamed area. 

 They are usually quite limited in number except in localized 

 inflanuuation induced bv animal parasites. There are fre(juently 

 observed in the liver, kidnev, and other tissues, foci com]iosed 

 of a mass of eosinophiles and appearing as inflammators' cen- 

 ters. These eosinophilic inflammatory foci are probal^h' the re- 

 sult of invasion of animal parasites. Eosinophiles are abundant 

 in the lesions of bursattae and in epizootic lymphangitis. Their 

 origin is, S(_) far as has been detenuined, from the blood, the 

 lymph and tissue spaces indirecth', and the Ijone marrow di- 

 rectly. The specific action of these cells in inflammation is 

 not known. They do not aid in the formation of new tissues. 

 ]\Iast cells or polymorjihonuclear leucoc}'tes with basophile 

 granules are oljserved in subacute inflammation (Adami). 

 Their origin is from bone marrow. Their nuclei apparently 

 become disintegrated in inflamed tissue. The significance of 

 these cells has not been determined. 



Lymphocytic invasion of the affected areas and an excess of 

 them in the blood characterize some of the slow .^oing c>r 

 chronic inflammatorv processes such as tuberculosis and ac- 

 tinomycosis. These cells also appear in afl-ected tissues in ihe 

 later stage of acute inflammation but are never ver\- abundai\t, 

 Thev ma}' ha\'e their origin from the blood, the Ivmph and 

 from adjacent lymphoid tissue. The large h'mphocytes mav 

 have their origin from the small Iymphoc}'tes. LvmphocA'tes 

 have a verv limited power of amoeboid movement. The^' ha\'e 

 never been observed to ingest bacteria although they ma\' in- 

 corporate fragments of destro^-ed tissue cells or other inert sub- 

 stances. These cells may jiartake in the formation a{ new tis- 

 sue but this has not yet been positi\'eK- determined. 



Cells other than leucocytes are sometimes observed in in- 

 flamiuatory foci. Endothelial cells, wandering connective tis- 

 sue cells, giant cells, and red blood corpuscles may be present in 

 inflamed areas. 



Endothelial cells are especially evident in serous membranes 

 afl:'ected with inflammation. They appear later in the process 

 than cither polymorphonuclear leucocytes or l}-mphocvtes. 

 Their origin is ])robably from pre-existing, like cells. They usu- 

 ally have a sluggish movement, are slightly phagocytic and 

 also ingest fragments or particles of inert substances. These 

 cells may be destroyed or they mav emigrate from the afifected 

 area. 



Wandering connective tissue cells are usually present in 

 inflamed tissues. These cells do not appear until some time 



