NOTES ON THE MUSCULAR CHANGES BROUGHT ABOUT BY 



INTERMUSCULAR INJECTION OF CALVES WITH THE 



VIRUS OF CONTAGIOUS PLEUROPNEUMONIA.^ 



By William Hutchins Boynton, 

 (From the Veterinary Division,^ Bureau of Agriculture, Manila, P. I.) 



In looking up the literature concerning the muscular changes 

 in pleuropneumonia, there has come to notice but one article 

 on the subject by Meyer, (i) who gives a very good description 

 of the changes. The writer agrees with him in practically 

 every respect, but will try to bring out some points of comparison 

 between the muscle and lung lesions which were not included 

 within the scope of his studies. 



The animals used in the experiment were young native calves, 

 apparently in vigorous health before they were inoculated, which 

 had the best of care during the entire experiment. 



The muscle tissues used for histological purposes were taken 

 from three calves, which died as a result of intermuscular in- 

 jection of lymph secured from the thoracic cavity of animals 

 dead of contagious pleuropneumonia. 



The. muscle tissue was fixed in formalin and, in some cases, in 

 Zenker's fluid. Both paraffin and frozen sections were made, 

 and stained with hsemotoxylin-eosin, Giemsa, Wright's stain, 

 Jenner's stain, and Weigert's special method for fibrin. 



Upon microscopic examination of the subcutaneous connective 

 tissue, the most striking change which one notices is its marked 

 distention, the tissue being infiltrated with a coagulated fibrin- 

 ous exudate. The connective-tissue fibers are either pushed to 

 one side or have undergone necrosis as a result of the coagula- 

 tion of exudate around them. 



Scattered through the distended connective-tissue spaces will 

 be noticed isolated or confluent dark-staining areas, which vary 



' Reprinted from Bull. No. 20, Bureau of Agriculture of the Government 

 of the Philippine Islands. — The Bureau of Agriculture is indebted to the 

 biological laboratory. Bureau of Science, for the use of the laboratory 

 facilities utilized in carrying out this work. 



•Archibald R. Ward, chief. 



525 



