72 BIOLOGY AND TECHNIQUE 



his ultra-microscopic organism was a parasite upon bacteria, adapted 

 specifically in different cases to various organisms. 



In 1920 Kabeshima 36 studied the D'Herelle phenomenon and 

 interpreted it as being due to ferment action. He believes that 

 D 'Herelle 's principle was a catalytic agent originating in the mucous 

 membranes of the intestinal canal, which induced enzyme digestion 

 of the organisms. In the cells of bacteria he assumes there exists 

 a preferment which is activated by the catalyst and leads to 

 autolysis of the organisms. 



In 1920, also, Bordet and Cuica 37 attacked the same problem 

 from an entirely different standpoint. Bordet injected guinea pigs 

 intraperitoneally three or four times with B. coli. One or two days 

 after the last injection, the peritoneal exudate was examined and 

 found to consist of an exudate rich in leucocytes in which still a 

 few organisms were present. When a few drops of such an exudate 

 were added to a normal B. coli culture, marked lytic powers were 

 noticed. A small quantity of the exudate resulted in a clearing up 

 of the normal broth culture, and a small amount of this original 

 mixture would do the same if added to successive cultures of normal 

 Colon bacilli. In other words, the lytic principle started in the 

 peritoneal exudate of guinea pigs, was kept going through successive 

 Colon cultures. This active principle, like that of D'Herelle, resisted 

 heating to from 60 to 65, and this sterile exudate would still 

 possess lytic powers for Colon cultures. It may be stated that 

 in Bordet 's experiments it was found that it was very difficult to 

 start the principle in this way, and that only isolated Colon cultures 

 lent themselves to successful experimentation. When a few drops 

 of a culture cleared in this way were added to an agar slant freshly 

 inoculated with normal Colon bacillus, no growth took place in those 

 parts which had been touched by the fluid, and colonies which 

 developed in or about this area soon became glassy and transparent. 

 In the same way, Bordet often found that dissolved cultures were 

 not entirely sterile on sub-culturing. A small number of colonies 

 developed, some of which had an extremely irregular outline. These 

 irregular colonies carried the lytic principle in subsequent genera- 

 tions. Bordet interpretes this phenomenon as the artificial produc- 



36 Kabeshima, Compt. Rend, do la Soc. Biol., 83, 1920. 



37 Bordet and Cuica, Compt. Bend, de la Soc. Biol., 88, 1920, 



