CHAPTER III 

 THE NATURE OF GENES 



1. The Generation of Genes 



As referred to above, primeval organisms presumably could 

 succeed in maintaining their structural pattern despite their easily 

 changeable character which they had secured for the purpose to 

 respond to stimuli, by making use of elementary bodies having high 

 content of nucleic acid. 



Such bodies or particles would decide the fate of a primeval orga- 

 nism when the organism combined with another type of organisms 

 having a different structure ; the one containing the nucleic acid-rich 

 particles of stronger structure would overcome and assimilize the 

 other, since the particles could govern the whole structure of the 

 organisms. Owing to their strong structure due to the high content 

 of nucleic acid, the particles even after freed from the organism 

 would be able to transmit their pattern to the other organisms having 

 weaker particles. In short, the same would result either when the 

 particle combined in a free state with weaker organisms or when com- 

 bined without being freed from the organism. 



At least strongly active phage particles produced from lysogenic 

 bacteria can be regarded as such representative bodies of the bacterial 

 cell. Only one type of a certain virus can multiply when two 

 different types simultaneously affect a host cell, a fact which is known 

 as interference phenomenon, and which has been studied with phage 

 especially in detail. 



The multiplication of a phage in a bacterial cell is the transmission 

 of the phage structure to the bacteria, whereby the bacteria are assi- 

 milized by the phage. Accordingly, it should necessarily follow that 

 in a bacterial cell affected simultaneously by two different phages 

 solely a strong phage can multiply, the weaker one being unable to 

 exert any influence. If, however, the strength of two phages is alike 

 both may multiply in a cell at the same time without interference ; 

 this is found to be actually the case. 



In this connection should be mentioned a very remarkable fact. 

 When a single bacterium is infected with a pair of phages like T2r+ 

 and T4r, one finds among the emerging viral progeny types which 



