CONTRIBUTIONS TO BIOLOGICAL STUDIES ON THE VIRUS OF CONTAGIOUS PLEURO-PNEUMONIA IN CATTLE

For effective control of contagious pleuro -pneumonia in cattle, it is believed of importance to ascertain the biological characters of the virus of the disease. Extensive studies for this purpose have been made abroad, so that there is a number of valuable informations relating to cultural and biochemical surveys. However, biological characteristics of the virus have not been yet thoroughly demonstrated. As shown in our former publication, in growing the virus on culture media some particular efforts should de made to obtain positive results. Moreover, as for the tenacity of the virus against physical and chemical influences, our knowledge seems to be almost lacking. The possibility of the cultivation of the virus in vivo by sealing broth inoculated with a small quantity of lymph from affected lungs in a collodion sack and placing it in the peritoneal cavity of a rabbit was first demonstrated by Nocard and Roux (1898). Later they succeeded in cultivating the virus in the peritoneal cavity of cattle by a similar procedure, and also in Martin's broth added with cattle or rabbit blood serum (6-8%). DujardinBeaumetz found Martin's peptone and Martin's broth agar containing blood serum to be suitable media for the development of the virus outside the animal body. Furthermore, Marino used broth added with a few drops of an alcoholic solution of eosin blue for the estimation of development of the virus in fluid media. Besides these investigators Bordet, Schmit, Poppe (1913), Giese (1922), Joseph, Heslop, and Dahmen published