CHAPTER VI 

 THE SHAPE OF VIRUS PARTICLES 



1. Tailed and Filamentous Virus Particles 



It is a well known fact that some phage has a tail like a tadpole. 

 If an elementary bundle in an elementary body failed to shrink, while 

 the other remaining bundles coagulated into a body, a virus particle 

 having a tail would be produced. The inability of shrinking of a 

 certain elementary bundle may be attributed to its peculiar chemical 

 composition ; if such a peculiar composition occurred in a certain 

 bundle of the body following the infection with some strain of the 

 virus, each virus particle produced would have a tail. 



Since the structural pattern induced in the protoplasm-protein by 

 a virus is governed by the kind of virus, it should naturally occur 

 that phages of some kind have a tail while others not. Not only 

 the production of a tail but also the degree of the shrinkage or that 

 of the decomposition or of the association of elementary bodies should 

 more or less be influenced by the pattern of the virus, so that particle 

 size w*ould be subjected to a certain extent to the kind of viruses even 

 when the cells affected are of a similar type, although the size is 

 chiefly determined, as already stated, by the cells from which the 

 virus is produced. According to our study (66), the particles of vac- 

 cinia virus recovered from infected rabbit testicles are a little smaller 

 than the normal particles from noninfected testicles. 



Glaser and Wyckoff (62) stated that normal particles from silk- 

 worms are rather more inhomogeneous in the sedimentation rate than 

 the virus particles isolated from the worms infected with polyhedrosis. 

 This may indicate that the elementary bodies of the silk-worm, when 

 affected by the virus, tend to decompose more extensively than the 

 normal bodies. Isolation of tailed particles from normal bacteria 

 seems to have never been reported. This may show that the occur- 

 rence of the peculiar structural change causing inability of shrinking 

 in a certain elementary bundle leading to the tail production cannot 

 be induced without certain phages. 



It has been reported that in the presence of proflavine bacterial 

 cells infected with phage underwent lysis without producing active 

 phage particles (67). The bacteria which usually produced tailed par- 

 ticles would yield, in the presence of proflavine, lysates consisting 



