VIII. REPLICATION OF VIRUS PATTERN 101 



glutinins, that is, "incomplete virus", possibly representing an immature 

 form of the virus. His calculations indicated that only one of 10,000 

 particles was infective in the third passage. In this case, if diluted al- 

 lantoic fluids were used instead of undiluted ones and a proper amount 

 of virus particles was inoculated, complete virus was produced instead 

 of the incomplete one. As previously stated, large sized particles, as a 

 rule, involve strong and complete virus, and further decomposition of 

 the particles into smaller fragments may result in the loss or decrease 

 in the infectivity ; on the other hand, it has been reported that this 

 "incomplete virus" is smaller in size than the normal infective virus 

 particles (126) (130). 



The above finding shows that the complete structure of virus fails 

 to be formed even after a prolonged period if environmental conditions 

 are not suitable. It has been reported that there occurs no multiplica- 

 tion of phage when the number of virus particles applied exceeds great- 

 ly the number of bacterial cells exposed, although the lysis of bacteria 

 takes place (131). This likewise may indicate the production of incom- 

 plete virus. Moreover, Shlesinger (132) showed that when mouse brain 

 is inoculated with a non-neurotropic strain of virus, production of com- 

 plement fixing antigen and haemoagglutinin occurred but there was no 

 production of infective virus. The yield of incomplete virus was pro- 

 portional to the amount of infectious virus originally inoculated. 



2. Change of Viruses Following Their Combination 

 with Host Cells 



Doermann and Anderson (123) have followed the production of a 

 phage in host bacterial cells by disrupting the cells with intense sonic 

 vibration at intervals after the infection, and have found that, up to 

 12 minutes after the infection, the disruption of the cells destroys their 

 ability to form plaques, although free phage particles are highly resist- 

 ant to such a treatment. They concluded from this evidence that in 

 the freshly formed complex the virus is in a state sensitive to sonic 

 vibration and that at the beginning of the infection the infecting virus 

 particles has lost through some mysterious transformation its resistance 

 to sonic vibration. 



As above stated, viruses when combined with cells should have to 

 unfold their structure in order to show their full pattern which is to 

 be replicated in the host cells. However, in the unfolded form viruses 

 may be labile unlike the virus in the coagulated coiled up state. Thus 

 the phage may become extremely sensitive to sonic vibration on the 

 combination with bacteria. 



