458 ILLINOIS STATE ACADEMY OF SCIENCE 



organisms. These parasites pass through the finest clay 

 filters, but can be cultivated only in the presence of the 

 bacteria. Bordet states the phenomena is a defensive 

 process due to the leucocytes which give to the organ- 

 isms an hereditary property of producing a lytic fer- 

 ment. The only difference between these two theories is 

 whether the lytic ferment is produced by an ultra-micro- 

 scopic virus or whether it is produced by the bacteria 

 themselves. Kabeshino claims that lysis is due to a 

 prodiastase present in the bacterial cell which is acti- 

 vated by a catalysor contained in filtrates of intestinal 

 contents; in other words, that lysis is due to a ferment 

 from the tissues. Salibeni has found a myxamoeba in 

 lytic filtrates. Elivia and Pozerski described the de- 

 struction of Shiga bacillus by salts of quinine. What- 

 ever the nature of the principle, however, it is certain 

 that in persons convalescing from disease, notably 

 typhoid fever, bacilliaiy dysentery and cholera, a sub- 

 stance is present in the stools that will dissolve the bac- 

 teria from which the patient is suffering when these two 

 are placed together. 



As was stated before, it is impossible to grow this lytic 

 principle, whatever it may be, except in the presence of 

 young cultures of bacteria, but bacteria free cultures will 

 remain active for as long as six months. Anaerobiosis 

 does not favor the lytic action. The material can be 

 passed from tube to tube of bacteria an indefinite num- 

 ber of times and will remain active in clear filtrates for 

 six months. In centrifuged specimens of filtrates, noth- 

 ing can be demonstrated by staining the sediment. How- 

 ever, when a little of the sediment is examined with the 

 ultra microscope, very fine points of light are seen danc- 

 ing in the medium. d'Herrelle claims these are the or- 

 ganisms in question. The principle reacts to physical 

 and chemical agents very much as do bacteria, being de- 

 stroyed by antiseptics and heat and being quite suscep- 

 tible to acids and alkalies, preferring a slightly alkaline 

 medium for growth. 



The lytic action of this ultra microscopic organism, if 

 such it is, can well be demonstrated in a test tube experi- 



