IX. METABOLISM 285 



metabolic activity of host cells. For instance, as already described, 

 phage is commonly produced in young, proliferating bacteria. Acker- 

 mann (105) was able to confirm that the yield of influenza virus was 

 apparently directly proportional to the residual oxygen consumption 

 of embryonated chick tissues. These facts may only show that young, 

 active cells possess protoplasm which is particularly suited for the 

 virus multiplication. 



Ackermann and Johnson (106) found that 2,4-dinitrophenol inhibits 

 completely the propagation of influenza virus in chorioallantoic mem- 

 brane, while this reagent shows no virucidal effect in vitro. In minced 

 preparations of chorioallantoic membrane the reagent was shown to 

 have a pronounced stimulating effect upon adenosine-triphosphatase, 

 and when this reagent was used with intact tissues, an excellent cor- 

 relation was found between the inhibition of viral propagation and 

 the stimulus of respiration and release of phosphate. From these 

 facts they concluded that the energy required for viral synthesis was 

 derived from the oxidative phosphorylative activity of the host tissue. 

 However, this conclusion might be somewhat rash, since it can also 

 be considered that the effect of the reagent upon the protoplasm may 

 be unfavourable for the production of the virus pattern though 

 favourable for the enzymatic action. Peculiar influences of a variety 

 ■of such reagents upon the production of virus pattern will be dis- 

 cussed in detail in the next Part. 



On studying the development of phage in bacteria "killed" by 

 ultraviolet or X-ray, Labaw et al. (107) have found that although the 

 phosphorus metabolism of the bacteria is greatly depressed by "kill- 

 ing," it will continue for a short time after the treatment, and it is 

 during this time that phage can multiply ; the yield of phage is large 

 even for completely killed cultures, if infection occurs immediately 

 after the treatment, but decreases with the time of incubation of the 

 treated bacteria before infection. This fact, however, may not show 

 that phosphorus metabolism is indispensable for the virus multipli- 

 cation. It may be more reasonable to interpret this fact as indicating 

 that for the virus multiplication the protoplasm structure could not be 

 so severely damaged as phosphorus metabolism was completely lost. 



The writer holds the opinion as discussed already that the prim- 

 ary organisms were generated and evolved by the mechanism by which 

 viruses multiply. If energy is required for this mechanism the theory 

 of the w^riter cannot be held, because no metabolic system is con- 

 sidered to have been present in the protoplasm-like masses in which 

 the organisms might develop. The fact that no energy appears to be 

 particularly needed for the action of the enzyme must be one of the 

 main reasons for which life could be raised on this globe. 



